nas to iscsi migration - pastebin.kmpr.at

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Nas to iscsi migration Guest on 9th November 2024 09:08:35 PM

what are realistic specs for a 4 bay iscsi that is hooked up to a proxmox cluster of three i5 9500t hosts (elitedesk 800 g5)? i have a 10gbe rj45 network for the servers ChatGPT: ChatGPT

Setting up a 4-bay iSCSI storage server for a Proxmox cluster with your existing setup and 10GbE network is a solid plan for shared storage. Here are some realistic specs to achieve good performance while balancing cost and reliability. Key Requirements

For your setup, the iSCSI server should offer:

Sufficient performance to handle the storage I/O demands of multiple virtual machines.
High availability for redundancy (RAID, power, and network).
Compatibility with Proxmox for iSCSI integration.
10GbE network capability to match your network speed.

Recommended Specifications for the 4-Bay iSCSI NAS

CPU

Processor: Intel Core i3, i5, or a low-power Xeon (e.g., Xeon E-2224). Since iSCSI doesn’t require very high compute power, an Intel Core i3 or entry-level Xeon is usually sufficient. However, an i5 gives you more headroom, especially if you need to handle multiple simultaneous iSCSI connections. Alternative: AMD Ryzen 3 or Ryzen 5. Ryzen CPUs generally offer more cores per dollar and are fine for iSCSI.
RAM

Capacity: 16GB is a good starting point, but 32GB is recommended if budget allows. Justification: iSCSI doesn’t need a lot of memory, but caching and file systems like ZFS benefit from more RAM, especially when handling multiple requests from VMs.
Storage Configuration

Disk Bays: Since this is a 4-bay setup, RAID 10 (striped and mirrored) is a good choice. It balances speed and redundancy. Drive Type: SSDs: If budget allows, SSDs (preferably enterprise or NAS-grade) will provide excellent performance, especially for virtualized workloads. HDDs: 4x NAS-grade HDDs (such as Seagate IronWolf or WD Red) in RAID 10 are more economical but slower than SSDs. You could consider hybrid setups (e.g., SSDs for frequently accessed data or ZFS cache) to optimize costs and performance. Capacity: Depends on your storage needs, but commonly, 1TB or 2TB drives are adequate for VM storage, especially if using SSDs. RAID Configuration: RAID 10 for redundancy and speed. ZFS with mirrors is also a popular choice for VM storage, especially in environments that may eventually grow.
Network Interface

10GbE NIC: Your server needs a 10GbE NIC with an RJ45 connector to match your network. Redundancy: If possible, dual 10GbE NICs (with one as a backup or aggregated) add redundancy and improve failover capability. You could consider Intel or Mellanox 10GbE NICs, which are typically reliable and well-supported.
Storage Controller

If you plan to use RAID, a hardware RAID controller (e.g., Dell PERC H730 or LSI MegaRAID) is an option. But, for flexibility, a simple HBA (Host Bus Adapter) with ZFS or software RAID is often preferable in NAS/iSCSI setups. ZFS Consideration: If using ZFS, don’t use a hardware RAID controller. Use an HBA instead, and let ZFS handle the RAID. This approach is popular for ZFS because it provides direct control over drives and data integrity.
Power Supply

Redundant Power Supply (if available): If uptime is critical, choose a chassis that supports dual PSUs for redundancy. UPS Backup: For additional reliability, an uninterruptible power supply (UPS) will help manage sudden power outages, which is especially important for a storage server.
Software and File System

Operating System: TrueNAS (previously FreeNAS) or Linux with iSCSI target tools are popular for handling iSCSI. TrueNAS Core (for ZFS support) or TrueNAS Scale (Linux-based, optimized for hyper-converged setups) is a good choice for simple management and iSCSI configuration. File System: ZFS is a solid option for VM storage due to its data integrity features, snapshots, and performance. Btrfs is another option, but ZFS is more common for iSCSI/NAS environments.
Chassis and Cooling

Chassis: Look for a small form factor (SFF) rack-mountable or desktop chassis that supports 4 hot-swappable bays. This is convenient for maintenance. Cooling: Proper airflow is crucial, especially with SSDs or 10GbE NICs that may generate heat. Make sure the chassis has good ventilation or active cooling fans.

Sample Hardware Build

Here’s a build suggestion based on your requirements:

CPU: Intel Core i5-10400 or Xeon E-2224
RAM: 16-32GB DDR4 ECC (if possible, for data integrity)
Storage:
    4x 2TB SSDs in RAID 10 for performance, or 4x 4TB HDDs if you need more capacity and are on a budget.
    Optional: 1-2 SSDs (200GB or more) for ZFS caching (L2ARC) if using HDDs.
Network: Intel or Mellanox 10GbE dual-port NIC, RJ45.
Chassis: A compact, 4-bay NAS chassis or small rackmount with adequate cooling.
Power: Single PSU (redundant if possible), with a small UPS for power backup.
OS: TrueNAS Core (if using ZFS) or Linux (Ubuntu or Debian) with iSCSI target software.

This setup should give you reliable shared storage over iSCSI, capable of handling VM workloads for your Proxmox cluster. The 10GbE network will also reduce latency, allowing you to take advantage of SSD speeds if you go that route. Du: i have the aoostar wtr pro in mind. currently i have openmediavault vm running on one proxmox host, which i would most likely extract to the iscsi machine. the 4 drives are 4x4tb ironwolf in zfs managed by omv

what is a good strategy to switch from smb/cifs as mass storage to iscsi and native pve disks on my zfs? ChatGPT: ChatGPT

Switching from an SMB/CIFS share to iSCSI with native Proxmox storage on ZFS will improve performance and simplify VM storage management. Here’s a good strategy for migrating your setup from OpenMediaVault (OMV) with SMB/CIFS to an iSCSI target on a dedicated storage server for Proxmox. Migration Strategy

Set Up the iSCSI Target on OpenMediaVault
    OMV has a plugin for iSCSI that allows you to share ZFS storage as iSCSI targets, making it accessible as a raw block device for Proxmox.
    Go to OMV's web interface and enable the iSCSI plugin. If you haven’t installed it yet, it can be added through OMV's plugin management.

Configure ZFS for iSCSI Volumes
    With ZFS, create separate ZVOLs (ZFS volumes) for each VM or storage need. ZVOLs are block devices optimized for iSCSI, making them suitable for VM storage.
    Each ZVOL can be configured with different properties, like record size and compression. You may want to keep the default record size (128K), as this works well for VM images.
    Example command to create a ZVOL:

    zfs create -V 100G omv/vm1

    This creates a 100GB ZVOL named vm1 on your ZFS pool omv.

Set Up iSCSI Target for Each ZVOL
    In OMV, navigate to Storage > iSCSI and add an iSCSI target for each ZVOL.
    Mapping ZVOLs to LUNs: Under OMV’s iSCSI configuration, each ZVOL can be mapped to a Logical Unit Number (LUN) within an iSCSI target, making it accessible from your Proxmox nodes.

Configure Proxmox to Connect to the iSCSI Target
    On each Proxmox node, go to Datacenter > Storage > Add > iSCSI.
    Provide the IP address of the OMV server and any required credentials. Proxmox will then discover the iSCSI LUNs available.
    Once connected, Proxmox will see each iSCSI target as a raw disk, allowing you to create VM disks or even shared storage.

Format the iSCSI Disk with LVM or ZFS
    Option 1: LVM on iSCSI: Create an LVM volume group on the iSCSI target. Proxmox can then use this LVM group to create individual VM disks.
        In Proxmox, use the LVM storage type and point it to the iSCSI target.
    Option 2: ZFS on Proxmox for Extra Control: If you prefer ZFS management on the Proxmox side, you could create a new ZFS pool on the iSCSI block device directly in Proxmox, giving you native ZFS snapshots and management per node.

Migrate VMs to iSCSI Storage
    Storage Migration: In Proxmox, use the storage migration feature to move VM disks from local storage to the new iSCSI storage.
    Alternatively, you can create new VM disks on the iSCSI storage and attach them to existing VMs as needed.

Phase Out SMB/CIFS for VM Data Storage
    Once your VMs are using iSCSI storage, you can start phasing out the SMB/CIFS shares for VM disk storage.
    Keep SMB/CIFS for shared file storage if needed, but use iSCSI for VM disk storage to reduce overhead and improve performance.

Optional Optimizations

Enable Compression on ZFS ZVOLs: If your storage needs are high and you want to save space, enable LZ4 compression on ZVOLs for better storage efficiency with minimal performance impact.
Setup a Dedicated iSCSI Network: If possible, dedicate a VLAN or even a separate NIC on your Proxmox nodes and storage server for iSCSI traffic to improve performance and isolate VM storage traffic from other network traffic.
Tune ZFS Parameters for iSCSI: For better performance on iSCSI workloads, set sync=always if data integrity is critical, and atime=off for reduced write load on VM disks.

Benefits of Switching to iSCSI with ZFS

Performance: Direct access to ZFS ZVOLs over iSCSI eliminates SMB overhead and improves VM storage performance.
Snapshot Capabilities: ZFS snapshots at the storage level offer consistency and quick recovery for VM storage.
Proxmox Compatibility: Direct iSCSI integration in Proxmox simplifies backup, migration, and management of VM disks.

This setup will give your Proxmox cluster high-performance, reliable shared storage and the flexibility of ZFS features without the overhead of SMB. It should also streamline VM management in Proxmox by moving VM storage to a more direct, efficient protocol. Du: since in only use openmediavault for simple samba shares by now, is it feasible to move to iscsi only on plain ubuntu or say install pve as host os with the zfs pool managed and provide iscsi to the other hosts that way? ChatGPT: ChatGPT

Yes, it’s definitely feasible to simplify your setup by moving to a plain Ubuntu server or even using Proxmox VE (PVE) directly as the host OS for managing your ZFS pool and providing iSCSI storage to the other Proxmox nodes. Both options have their pros and cons, so let's break down the two approaches and their practicality. Option 1: Plain Ubuntu with ZFS and iSCSI

This approach involves setting up a lightweight Ubuntu server with ZFS to manage your storage pool and using iSCSI to share storage with your Proxmox nodes. Steps:

Install Ubuntu Server: Use a minimal install of Ubuntu Server, which is lighter than OMV.
Install ZFS on Linux: Install ZFS using apt install zfsutils-linux to manage your ZFS pool on Ubuntu.
Create and Configure ZFS Pool: Import your existing ZFS pool (zpool import omv) or create a new one if starting fresh.
Set Up iSCSI:
    Install targetcli or tgt for iSCSI target configuration:

    sudo apt install targetcli-fb

    Configure ZFS ZVOLs for each VM or storage volume you want to share over iSCSI.
    Use targetcli to set up iSCSI targets and map the ZVOLs as LUNs.

Advantages:

Lightweight and Customizable: Ubuntu gives you a lean system without extra overhead, and you only install the necessary packages.
Separation of Storage and Compute: This separates storage management from Proxmox, which can be a benefit if you ever want to move the storage server to another system.
Stable and Reliable: Ubuntu’s LTS releases are stable, and you can easily set up a simple, reliable storage server.

Disadvantages:

No Proxmox Management: You won’t have Proxmox’s built-in ZFS and iSCSI management features. However, since iSCSI is a network protocol, it works seamlessly with Proxmox as an iSCSI target.
Manual Setup and Maintenance: You’ll need to manually configure and manage iSCSI and ZFS, which adds some administrative overhead.

This setup would be ideal if you’re comfortable managing ZFS and iSCSI from the command line and want a separate, dedicated storage server for your Proxmox cluster. Option 2: Install Proxmox VE as the Host OS and Use It for iSCSI Storage Management

Installing Proxmox VE as the host OS on your storage server is also a practical option, and it has some added advantages, especially if you’re already familiar with Proxmox. Steps:

Install Proxmox VE on the Storage Server: Install PVE as you would on a regular node.
Create and Import ZFS Pool:
    Use Proxmox’s web GUI to import your ZFS pool (omv) or create a new one directly within Proxmox.
Set Up iSCSI on Proxmox:
    Since PVE doesn’t have a built-in iSCSI target service, you’ll still need to install targetcli or tgt to configure iSCSI targets.
    Set up ZFS ZVOLs within Proxmox and export each ZVOL as a separate LUN over iSCSI.

Advantages:

Unified Proxmox Management: You’ll benefit from Proxmox’s built-in ZFS management tools, and you can manage your ZFS pool directly from the Proxmox web interface.
Native ZFS Integration: Proxmox has native support for ZFS, making tasks like snapshots, backups, and pool monitoring easier.
Future Flexibility: You could use this Proxmox instance for lightweight container hosting (e.g., backups or monitoring tools) without impacting storage performance.
Simplified Administration: This setup allows all your Proxmox nodes to have a consistent management interface, and there’s no need to manage another OS outside of Proxmox.

Disadvantages:

Less Separation of Roles: This setup combines storage and hypervisor roles, which may lead to some complexity if the storage server is also running VMs or containers (although it’s manageable if the load is light).
No Built-in iSCSI Target Service in Proxmox: You’ll still need to manage iSCSI through targetcli, as Proxmox doesn’t natively support creating iSCSI targets directly.

This approach is ideal if you prefer the ease of use of Proxmox’s ZFS management tools and would like everything in a single management interface. Additionally, using Proxmox on the storage server makes future expansion simpler if you ever need to use this server for lightweight tasks beyond storage. Additional Considerations

ZFS Snapshots and Backups: Both approaches allow you to take advantage of ZFS snapshots for backups, which you can integrate with Proxmox’s backup tools.
Network Configuration: If using iSCSI over a dedicated 10GbE network, ensure the iSCSI traffic is on a separate VLAN or subnet to isolate it from other Proxmox management traffic.
Performance Tuning: Both setups will allow you to enable ZFS settings like atime=off, compression=on, and sync=standard for better performance on iSCSI-based VM storage.

Summary

Plain Ubuntu: Ideal if you prefer a minimalist approach with separate storage management outside of Proxmox. This keeps roles separate but requires some manual setup.
Proxmox VE on Storage Server: Best if you prefer a unified interface for storage and ZFS management and may use the server for other lightweight tasks. It’s easy to set up and manage with Proxmox’s web UI, but requires using an external iSCSI configuration tool.

Both setups can work well in your Proxmox environment. The Proxmox-as-OS option might offer a more streamlined experience since you’re already familiar with it, especially if you want simpler management across all nodes in the cluster. Du: will i have to create volumes for each vm and lxc i have and will have in the future outside proxmox? this is not 100% what i want... maybe better make a zvol aof 100% the zfs raid fs and put it as target in pve? ChatGPT: ChatGPT

Yes, if you go the route of using individual ZFS volumes (ZVOLs) as iSCSI targets, you would indeed need to create separate ZVOLs for each VM or container. However, it sounds like you'd prefer a simpler setup where you can allocate storage dynamically within Proxmox without pre-creating individual volumes on the storage server.

Here's a way to streamline the setup by creating a single, large ZVOL to act as an iSCSI target. Proxmox can then manage the space within this volume using LVM, giving you flexibility and avoiding the need to manually create new ZVOLs for each VM or container. Simplified Approach: Single Large ZVOL as iSCSI Target Managed by Proxmox

Create a Large ZVOL on the ZFS Pool:
    On your storage server (running either Ubuntu or Proxmox as the base), create a single, large ZVOL that spans most of your ZFS pool capacity.
    For example, if your ZFS pool is omv, you can create a ZVOL named pve_storage using a command like:

    zfs create -V 13T omv/pve_storage

    This will create a 13TB ZVOL, which Proxmox can treat as a single iSCSI target.

Export the ZVOL as an iSCSI Target:
    Use targetcli or tgt to set up an iSCSI target for the ZVOL (omv/pve_storage).
    Map this ZVOL as a LUN on the iSCSI target, so it can be seen as a single large disk by Proxmox.

Connect Proxmox to the iSCSI Target:
    In Proxmox, go to Datacenter > Storage > Add > iSCSI and add the iSCSI target you just created.
    Provide the IP address of your storage server and the iSCSI target name, then save the configuration.

Format the iSCSI Disk with LVM in Proxmox:
    Once Proxmox detects the iSCSI target, format it with LVM to enable Proxmox to manage storage within that large ZVOL.
    Go to Datacenter > Storage > Add > LVM, and select the iSCSI disk as the base for a new LVM volume group.
    This setup will allow Proxmox to create logical volumes dynamically within the ZVOL-backed LVM group, which will serve as VM disks or container storage.

Use the LVM Storage in Proxmox for VM and LXC Storage:
    Now, in Proxmox, you can select this LVM-based storage as a target for VM and LXC disks.
    Proxmox will handle creating and managing VM and container disks dynamically within the LVM volume group, giving you flexibility similar to a local storage setup.

Benefits of This Approach

Dynamic Storage Allocation: Proxmox will manage individual VM and container disks within the large iSCSI-backed LVM volume group, eliminating the need to pre-create ZVOLs for each VM or container.
Centralized Storage: By using a single large ZVOL, you centralize management on the storage server, with Proxmox managing VM storage allocation within that large volume.
Reduced Complexity: You avoid the manual work of creating ZVOLs for each new VM or container, which simplifies maintenance and scaling.

Potential Considerations

Snapshot Limitations: ZFS snapshots at the ZVOL level will snapshot the entire large ZVOL rather than individual VMs. If you need per-VM snapshots, Proxmox’s LVM-based snapshots will be limited compared to ZFS snapshots. However, Proxmox backups and snapshot features on this setup will work as expected.
Performance Optimization: Monitor the performance of the large ZVOL. ZFS and iSCSI generally handle this well, but adjust settings like recordsize and sync on the ZVOL to optimize for VM workloads.

Summary

This approach balances flexibility and simplicity by using a single ZVOL as an iSCSI target. Proxmox can then manage individual VM and container storage volumes within the LVM layer on this target, effectively turning your storage server into a centralized storage system while keeping Proxmox in control of storage allocation. This setup allows you to expand VM and container storage dynamically without needing to adjust anything on the storage server. Du: does my zfs pool has to be empty? how easy can I expand the zvol? eg. i have 10tb, 3 are occupied with my media lib. can i make a 7tb zvol, move my media there and then clear the now freed 3tb and expand the 7tb zvol to the full 10tb available? ChatGPT: ChatGPT

No, your ZFS pool doesn't have to be empty to create and expand ZVOLs. ZFS allows you to create ZVOLs (virtual block devices) of any size, and you can grow them dynamically as long as there's available space in your pool.

Here’s how you can approach your situation where you have a 10TB ZFS pool, with 3TB occupied by your media library, and you want to create a ZVOL of 7TB, move your data, and then expand it to use the full 10TB available: Step-by-Step Process

Create a 7TB ZVOL:
    You can create a ZVOL of 7TB from your pool without needing to worry about the existing data occupying 3TB of space. ZFS will allocate the required space for the ZVOL from the free space in the pool, which is 7TB in your case.
    Run the following command to create a 7TB ZVOL:

zfs create -V 7T omv/your_zvol_name

This command creates a 7TB virtual block device (your_zvol_name) under your ZFS pool (omv).

Move Your Data to the New ZVOL:

You can then move your media library or data from your current ZFS dataset (which is taking up 3TB) to the newly created ZVOL.
You can use rsync or a similar tool to transfer data from one dataset to another, making sure you preserve permissions and metadata:

rsync -avh /path/to/old/dataset/ /path/to/your_zvol_mountpoint/

Delete the Old Data:

Once the data is safely moved to the new ZVOL, you can delete the old dataset that’s taking up the 3TB. This frees up the 3TB of space, allowing it to be reclaimed in the pool.

zfs destroy omv/old_dataset

Expand the ZVOL to Use the Full 10TB:

Now that you have freed up the 3TB by moving your media library and deleting the old dataset, you can expand the ZVOL to use the full 10TB of available space.
To expand the ZVOL, use the following command:

    zfs set volsize=10T omv/your_zvol_name

    This will resize the ZVOL to occupy all 10TB of space in your pool.

Important Notes

ZFS Space Management: ZFS is quite flexible with its space allocation. It doesn’t pre-allocate the entire space when you create a ZVOL; it dynamically uses space as data is written. The ZVOL will grow in size as data is written to it, up to the maximum size you specify.

Expanding ZVOLs: Expanding a ZVOL is simple and doesn’t require you to move data around or destroy any existing data. As long as the ZFS pool has free space, expanding a ZVOL is a straightforward operation. When you run the zfs set volsize=10T command, ZFS will resize the ZVOL, and the additional space will be available for use.

Data Integrity: Always ensure you have a backup of your important data before performing any operations like resizing or moving data. While ZFS is highly reliable, it’s always best practice to have backups.

Performance Considerations: If you’re moving a large amount of data, ensure you have good network or disk throughput to minimize downtime. ZFS provides excellent tools like snapshots, which can allow you to take a point-in-time backup before moving data.

Conclusion

No, your ZFS pool doesn’t need to be empty to create and expand a ZVOL. You can create a 7TB ZVOL, move your data, and then expand it to use the full available space in your pool without issue. ZFS makes this process relatively easy with its dynamic volume management, and you can manage space efficiently as long as you have free space in the pool. Just make sure to safely move and verify your data before expanding the ZVOL. Du: will there be actual io when i shift the data? 3tb read and write are timeconsuming and wear the disks ChatGPT: ChatGPT

Yes, there will be actual I/O when you move your data, as you're reading from one location (the source dataset) and writing to another (the target ZVOL). This will result in significant read and write operations, and as you noted, it can be time-consuming and put wear on the disks, especially for large volumes like your 3TB of data.

However, there are ways to minimize the impact of these operations, and I'll outline a few strategies you can use:

Use rsync with Optimizations:

rsync is a powerful tool for data migration because it can be optimized to minimize disk I/O. You can use it with specific flags to optimize the read and write operations:

--inplace: This option allows rsync to write to the target directly rather than creating temporary files, which reduces the additional writes needed.
--dry-run: Before actually moving the data, run rsync with the --dry-run flag to see how much data will be moved and make sure everything is set up correctly. This is a way to avoid surprises.
--bwlimit: If you want to limit the rate at which rsync performs the transfer to reduce load on your system, you can use the --bwlimit option to throttle the bandwidth (e.g., --bwlimit=100M to limit the speed to 100MB/s).

Example rsync command for minimal I/O:

rsync -avh --inplace --bwlimit=100M /path/to/source/ /path/to/destination/

This command will move the data from your source to your destination, with minimal extra I/O overhead and bandwidth control.

Use ZFS Snapshots and Clones (Optional):

If you're running this migration on a ZFS-backed storage system, one approach to reduce I/O and risk of wear is to use ZFS snapshots and clones:

Snapshot the Source Dataset: Before migrating the data, you can create a snapshot of the original dataset. This creates a read-only point-in-time copy without additional disk writes.

zfs snapshot omv/source_dataset@snapshot_name

Create a ZFS Clone: Once the snapshot is taken, you can create a ZFS clone of the snapshot, which is writable and can be moved to the target ZVOL. Since clones don’t require additional physical writes at first, it reduces I/O on the source dataset until data is modified.

zfs clone omv/source_dataset@snapshot_name omv/clone_for_move

Move Data from Clone: You can now move data from the clone to the target ZVOL with rsync or a similar tool. After the move, you can destroy the clone.

Cleanup: Once the data is safely transferred, you can destroy the clone and snapshot:

zfs destroy omv/source_dataset@snapshot_name
zfs destroy omv/clone_for_move

This method doesn’t require physical copying of the data and allows you to migrate without causing significant I/O to the original data.

Schedule Transfers During Off-Peak Hours:

If the data migration has to occur during a time when the system is under load, consider performing the transfer during off-peak hours when there’s less disk activity. This minimizes the impact on other services running on the same system.

Consider Using ZFS send and receive (for Dataset Moves):

If you're migrating entire datasets (instead of just moving individual files), you can use the ZFS send/receive method. This can be more efficient because it only sends the data that has changed (i.e., it’s more incremental and doesn’t re-read or rewrite data unnecessarily).

Example for sending and receiving:

zfs snapshot omv/source_dataset@snapshot_name zfs send omv/source_dataset@snapshot_name | zfs receive omv/target_dataset

This operation may be faster than a full rsync and could be a more efficient way to move the data without putting as much wear on the disks.

Move Data in Phases:

Rather than moving the entire 3TB of data all at once, you could break the transfer into smaller, more manageable chunks. This reduces the load on the disks at any given time. For example:

Move a few hundred gigabytes at a time.
Run multiple smaller rsync commands sequentially or in parallel.

This might take longer in total but will help distribute the load across the migration process and prevent the system from being overwhelmed.

Monitor Disk Health and Wear:

ZFS is designed with data integrity and wear management in mind, but it's still a good idea to monitor the health of your disks, especially if you're doing a large migration. Use tools like smartctl to monitor disk health and ensure no errors or warnings are occurring during the migration process.

You can check SMART status with:

smartctl -a /dev/sdX

Also, monitor the I/O load and disk usage during the transfer using iostat, zpool iostat, or other system monitoring tools to make sure that the system isn't under heavy load. Conclusion

Yes, moving 3TB of data will result in I/O operations (reads and writes) that will take time and can contribute to wear on the disks, but there are ways to minimize the impact. Using rsync with optimizations, leveraging ZFS snapshots and clones, scheduling the migration during off-peak hours, or even using zfs send/receive can all help reduce the amount of actual disk I/O required and spread the load over time. Be sure to monitor disk health throughout the process, and if possible, break the transfer into smaller steps to further minimize the impact. Du: when i finally have my masss torage as iscsi available in pve? will i have the base os of my vm and lxc on my ssd and only mass storage on hdd provided as extra disk to the guests? that way i have the os on fast ssd and the less volatile data on hdd ChatGPT: ChatGPT

Yes, you can absolutely configure your Proxmox Virtual Environment (PVE) in such a way that the base OS (both for VMs and LXC containers) resides on SSD storage while the mass storage (for less volatile data, like media libraries, archives, or backup data) is placed on HDD storage via iSCSI.

Here's a more detailed breakdown of how you can set this up:

Install the Base OS of VMs and LXCs on SSD:

VMs: When you create a virtual machine in Proxmox, you can specify the location of the virtual disks. In this case, you would want to store the VM base disk on your fast SSD. During VM creation, choose the SSD storage as the target for the virtual disk(s). This ensures that the operating system and any fast-access data (like application files or databases) will benefit from the speed of the SSD. LXCs: Similarly, when creating LXC containers, you can configure the storage location for their root filesystems. Store these root filesystems on the SSD for improved performance. In Proxmox, this would involve selecting a storage backend (like local SSD) for the LXC container.
Attach Mass Storage (iSCSI) to VMs/LXCs:

You can use iSCSI to provide extra storage (like your 10TB ZFS pool or other storage volumes) to your VMs or LXCs as additional virtual disks. Once your iSCSI target (your OpenMediaVault server or the Proxmox host with ZFS and iSCSI) is available and configured: For VMs: You can add the iSCSI LUN (Logical Unit Number) as a virtual disk to the VM. The disk can be formatted and mounted inside the VM to store less-volatile data, such as backups, media files, or large datasets. For LXCs: You can similarly mount iSCSI storage inside an LXC container to store large data volumes.
Steps to Set Up Mass Storage via iSCSI for VMs/LXCs:

On Proxmox (Host) Side: Make sure the iSCSI initiator on the Proxmox host is configured to connect to the iSCSI target. Use iscsiadm or Proxmox’s web interface to connect to the iSCSI target and present the LUN to the Proxmox host. Create a storage definition for the iSCSI LUN in Proxmox (either via the GUI or the /etc/pve/storage.cfg file). This allows you to use the iSCSI storage as a backend for VM disks or as additional storage for LXCs.

Example configuration for Proxmox storage (/etc/pve/storage.cfg):

iscsi: iscsi-storage portal xxx.xxx.xxx.xxx target iqn.1993-08.org.debian:01:abcdef1234 username your-iscsi-user password your-iscsi-password

On the VM Side: Once the iSCSI storage is available on Proxmox, you can add the iSCSI LUN as a new disk to your VM. When configuring the VM, in the "Hardware" section, you would add a new disk, selecting the iSCSI storage you configured earlier as the disk target. Format this disk within the VM and mount it where appropriate for your data.

On the LXC Side: For LXCs, you can mount the iSCSI disk as a block device directly or use a shared directory setup. Use a mount command inside the LXC or define the mount in the LXC config file to make the iSCSI volume accessible.
Advantages of This Setup:

Performance: By keeping the base OS and application data on fast SSD storage, your VMs and LXCs will benefit from the performance advantages of SSDs, such as faster boot times and lower latency for OS-level operations and applications. Separation of Data: Storing less-volatile data (like media, large files, or backups) on HDDs via iSCSI provides you with ample storage space at a lower cost, without sacrificing SSD performance for the base OS and critical data. Flexibility: If you need to expand storage, you can do so on the iSCSI target without impacting the performance of your SSD-based base OS or VMs. Scalability: Your storage setup can grow by simply adding more iSCSI targets or expanding the ZFS pool without affecting the underlying VM and LXC setups.
Considerations:

Network Bandwidth: Since you're using 10GbE for networking, ensure that your iSCSI traffic can fully utilize this bandwidth. iSCSI over a 10GbE network will allow for high-speed access to your mass storage, but make sure that the network is configured correctly and isn’t congested. IO Performance: While SSDs provide excellent performance, HDDs are much slower, especially for random access. Ensure that the mass storage on the HDDs via iSCSI is used appropriately for workloads that don't require high IOPS (e.g., media storage, backups, archives). ZFS Considerations: ZFS is a great choice for managing storage with redundancy and data integrity. However, if your mass storage is going to handle many writes (such as large file servers), you may need to ensure that your ZFS setup is optimized for performance (e.g., proper use of compression, deduplication, and caching) to minimize overhead on the storage system.

Conclusion

Yes, it is entirely feasible to set up Proxmox such that the base OS of your VMs and LXCs reside on SSD storage for fast performance, while mass storage (for large, less-volatile data) is provided via iSCSI from your HDD-based storage. This setup maximizes both performance (for the OS) and capacity (for mass storage), and gives you flexibility in managing your storage resources efficiently.

Letzte Pastes

Raw Paste

what are realistic specs for a 4 bay iscsi that is hooked up to a proxmox cluster of three i5 9500t hosts (elitedesk 800 g5)? i have a 10gbe rj45 network for the servers
ChatGPT:
ChatGPT

For your setup, the iSCSI server should offer:

Sufficient performance to handle the storage I/O demands of multiple virtual machines.
    High availability for redundancy (RAID, power, and network).
    Compatibility with Proxmox for iSCSI integration.
    10GbE network capability to match your network speed.

Recommended Specifications for the 4-Bay iSCSI NAS
1. CPU

Processor: Intel Core i3, i5, or a low-power Xeon (e.g., Xeon E-2224).
    Since iSCSI doesn’t require very high compute power, an Intel Core i3 or entry-level Xeon is usually sufficient. However, an i5 gives you more headroom, especially if you need to handle multiple simultaneous iSCSI connections.
    Alternative: AMD Ryzen 3 or Ryzen 5. Ryzen CPUs generally offer more cores per dollar and are fine for iSCSI.

2. RAM

Capacity: 16GB is a good starting point, but 32GB is recommended if budget allows.
    Justification: iSCSI doesn’t need a lot of memory, but caching and file systems like ZFS benefit from more RAM, especially when handling multiple requests from VMs.

3. Storage Configuration

Disk Bays: Since this is a 4-bay setup, RAID 10 (striped and mirrored) is a good choice. It balances speed and redundancy.
    Drive Type:
        SSDs: If budget allows, SSDs (preferably enterprise or NAS-grade) will provide excellent performance, especially for virtualized workloads.
        HDDs: 4x NAS-grade HDDs (such as Seagate IronWolf or WD Red) in RAID 10 are more economical but slower than SSDs. You could consider hybrid setups (e.g., SSDs for frequently accessed data or ZFS cache) to optimize costs and performance.
    Capacity: Depends on your storage needs, but commonly, 1TB or 2TB drives are adequate for VM storage, especially if using SSDs.
    RAID Configuration: RAID 10 for redundancy and speed. ZFS with mirrors is also a popular choice for VM storage, especially in environments that may eventually grow.

4. Network Interface

10GbE NIC: Your server needs a 10GbE NIC with an RJ45 connector to match your network.
    Redundancy: If possible, dual 10GbE NICs (with one as a backup or aggregated) add redundancy and improve failover capability. You could consider Intel or Mellanox 10GbE NICs, which are typically reliable and well-supported.

5. Storage Controller

If you plan to use RAID, a hardware RAID controller (e.g., Dell PERC H730 or LSI MegaRAID) is an option. But, for flexibility, a simple HBA (Host Bus Adapter) with ZFS or software RAID is often preferable in NAS/iSCSI setups.
    ZFS Consideration: If using ZFS, don’t use a hardware RAID controller. Use an HBA instead, and let ZFS handle the RAID. This approach is popular for ZFS because it provides direct control over drives and data integrity.

6. Power Supply

Redundant Power Supply (if available): If uptime is critical, choose a chassis that supports dual PSUs for redundancy.
    UPS Backup: For additional reliability, an uninterruptible power supply (UPS) will help manage sudden power outages, which is especially important for a storage server.

7. Software and File System

Operating System: TrueNAS (previously FreeNAS) or Linux with iSCSI target tools are popular for handling iSCSI. TrueNAS Core (for ZFS support) or TrueNAS Scale (Linux-based, optimized for hyper-converged setups) is a good choice for simple management and iSCSI configuration.
    File System: ZFS is a solid option for VM storage due to its data integrity features, snapshots, and performance. Btrfs is another option, but ZFS is more common for iSCSI/NAS environments.

8. Chassis and Cooling

Chassis: Look for a small form factor (SFF) rack-mountable or desktop chassis that supports 4 hot-swappable bays. This is convenient for maintenance.
    Cooling: Proper airflow is crucial, especially with SSDs or 10GbE NICs that may generate heat. Make sure the chassis has good ventilation or active cooling fans.

Sample Hardware Build

Here’s a build suggestion based on your requirements:

CPU: Intel Core i5-10400 or Xeon E-2224
    RAM: 16-32GB DDR4 ECC (if possible, for data integrity)
    Storage:
        4x 2TB SSDs in RAID 10 for performance, or 4x 4TB HDDs if you need more capacity and are on a budget.
        Optional: 1-2 SSDs (200GB or more) for ZFS caching (L2ARC) if using HDDs.
    Network: Intel or Mellanox 10GbE dual-port NIC, RJ45.
    Chassis: A compact, 4-bay NAS chassis or small rackmount with adequate cooling.
    Power: Single PSU (redundant if possible), with a small UPS for power backup.
    OS: TrueNAS Core (if using ZFS) or Linux (Ubuntu or Debian) with iSCSI target software.

This setup should give you reliable shared storage over iSCSI, capable of handling VM workloads for your Proxmox cluster. The 10GbE network will also reduce latency, allowing you to take advantage of SSD speeds if you go that route.
Du:
i have the aoostar wtr pro in mind. currently i have openmediavault vm running on one proxmox host, which i would most likely extract to the iscsi machine. 
the 4 drives are 4x4tb ironwolf in zfs managed by omv

what is a good strategy to switch from smb/cifs as mass storage to iscsi and native pve disks on my zfs?
ChatGPT:
ChatGPT

Set Up the iSCSI Target on OpenMediaVault
        OMV has a plugin for iSCSI that allows you to share ZFS storage as iSCSI targets, making it accessible as a raw block device for Proxmox.
        Go to OMV's web interface and enable the iSCSI plugin. If you haven’t installed it yet, it can be added through OMV's plugin management.

Configure ZFS for iSCSI Volumes
        With ZFS, create separate ZVOLs (ZFS volumes) for each VM or storage need. ZVOLs are block devices optimized for iSCSI, making them suitable for VM storage.
        Each ZVOL can be configured with different properties, like record size and compression. You may want to keep the default record size (128K), as this works well for VM images.
        Example command to create a ZVOL:

zfs create -V 100G omv/vm1

This creates a 100GB ZVOL named vm1 on your ZFS pool omv.

Set Up iSCSI Target for Each ZVOL
        In OMV, navigate to Storage > iSCSI and add an iSCSI target for each ZVOL.
        Mapping ZVOLs to LUNs: Under OMV’s iSCSI configuration, each ZVOL can be mapped to a Logical Unit Number (LUN) within an iSCSI target, making it accessible from your Proxmox nodes.

Configure Proxmox to Connect to the iSCSI Target
        On each Proxmox node, go to Datacenter > Storage > Add > iSCSI.
        Provide the IP address of the OMV server and any required credentials. Proxmox will then discover the iSCSI LUNs available.
        Once connected, Proxmox will see each iSCSI target as a raw disk, allowing you to create VM disks or even shared storage.

Format the iSCSI Disk with LVM or ZFS
        Option 1: LVM on iSCSI: Create an LVM volume group on the iSCSI target. Proxmox can then use this LVM group to create individual VM disks.
            In Proxmox, use the LVM storage type and point it to the iSCSI target.
        Option 2: ZFS on Proxmox for Extra Control: If you prefer ZFS management on the Proxmox side, you could create a new ZFS pool on the iSCSI block device directly in Proxmox, giving you native ZFS snapshots and management per node.

Migrate VMs to iSCSI Storage
        Storage Migration: In Proxmox, use the storage migration feature to move VM disks from local storage to the new iSCSI storage.
        Alternatively, you can create new VM disks on the iSCSI storage and attach them to existing VMs as needed.

Phase Out SMB/CIFS for VM Data Storage
        Once your VMs are using iSCSI storage, you can start phasing out the SMB/CIFS shares for VM disk storage.
        Keep SMB/CIFS for shared file storage if needed, but use iSCSI for VM disk storage to reduce overhead and improve performance.

Optional Optimizations

Enable Compression on ZFS ZVOLs: If your storage needs are high and you want to save space, enable LZ4 compression on ZVOLs for better storage efficiency with minimal performance impact.
    Setup a Dedicated iSCSI Network: If possible, dedicate a VLAN or even a separate NIC on your Proxmox nodes and storage server for iSCSI traffic to improve performance and isolate VM storage traffic from other network traffic.
    Tune ZFS Parameters for iSCSI: For better performance on iSCSI workloads, set sync=always if data integrity is critical, and atime=off for reduced write load on VM disks.

Benefits of Switching to iSCSI with ZFS

Performance: Direct access to ZFS ZVOLs over iSCSI eliminates SMB overhead and improves VM storage performance.
    Snapshot Capabilities: ZFS snapshots at the storage level offer consistency and quick recovery for VM storage.
    Proxmox Compatibility: Direct iSCSI integration in Proxmox simplifies backup, migration, and management of VM disks.

This setup will give your Proxmox cluster high-performance, reliable shared storage and the flexibility of ZFS features without the overhead of SMB. It should also streamline VM management in Proxmox by moving VM storage to a more direct, efficient protocol.
Du:
since in only use openmediavault for simple samba shares by now, is it feasible to move to iscsi only on plain ubuntu or say install pve as host os with the zfs pool managed and provide iscsi to the other hosts that way?
ChatGPT:
ChatGPT

This approach involves setting up a lightweight Ubuntu server with ZFS to manage your storage pool and using iSCSI to share storage with your Proxmox nodes.
Steps:

Install Ubuntu Server: Use a minimal install of Ubuntu Server, which is lighter than OMV.
    Install ZFS on Linux: Install ZFS using apt install zfsutils-linux to manage your ZFS pool on Ubuntu.
    Create and Configure ZFS Pool: Import your existing ZFS pool (zpool import omv) or create a new one if starting fresh.
    Set Up iSCSI:
        Install targetcli or tgt for iSCSI target configuration:

sudo apt install targetcli-fb

Configure ZFS ZVOLs for each VM or storage volume you want to share over iSCSI.
        Use targetcli to set up iSCSI targets and map the ZVOLs as LUNs.

Advantages:

Lightweight and Customizable: Ubuntu gives you a lean system without extra overhead, and you only install the necessary packages.
    Separation of Storage and Compute: This separates storage management from Proxmox, which can be a benefit if you ever want to move the storage server to another system.
    Stable and Reliable: Ubuntu’s LTS releases are stable, and you can easily set up a simple, reliable storage server.

Disadvantages:

No Proxmox Management: You won’t have Proxmox’s built-in ZFS and iSCSI management features. However, since iSCSI is a network protocol, it works seamlessly with Proxmox as an iSCSI target.
    Manual Setup and Maintenance: You’ll need to manually configure and manage iSCSI and ZFS, which adds some administrative overhead.

This setup would be ideal if you’re comfortable managing ZFS and iSCSI from the command line and want a separate, dedicated storage server for your Proxmox cluster.
Option 2: Install Proxmox VE as the Host OS and Use It for iSCSI Storage Management

Installing Proxmox VE as the host OS on your storage server is also a practical option, and it has some added advantages, especially if you’re already familiar with Proxmox.
Steps:

Install Proxmox VE on the Storage Server: Install PVE as you would on a regular node.
    Create and Import ZFS Pool:
        Use Proxmox’s web GUI to import your ZFS pool (omv) or create a new one directly within Proxmox.
    Set Up iSCSI on Proxmox:
        Since PVE doesn’t have a built-in iSCSI target service, you’ll still need to install targetcli or tgt to configure iSCSI targets.
        Set up ZFS ZVOLs within Proxmox and export each ZVOL as a separate LUN over iSCSI.

Advantages:

Unified Proxmox Management: You’ll benefit from Proxmox’s built-in ZFS management tools, and you can manage your ZFS pool directly from the Proxmox web interface.
    Native ZFS Integration: Proxmox has native support for ZFS, making tasks like snapshots, backups, and pool monitoring easier.
    Future Flexibility: You could use this Proxmox instance for lightweight container hosting (e.g., backups or monitoring tools) without impacting storage performance.
    Simplified Administration: This setup allows all your Proxmox nodes to have a consistent management interface, and there’s no need to manage another OS outside of Proxmox.

Disadvantages:

Less Separation of Roles: This setup combines storage and hypervisor roles, which may lead to some complexity if the storage server is also running VMs or containers (although it’s manageable if the load is light).
    No Built-in iSCSI Target Service in Proxmox: You’ll still need to manage iSCSI through targetcli, as Proxmox doesn’t natively support creating iSCSI targets directly.

ZFS Snapshots and Backups: Both approaches allow you to take advantage of ZFS snapshots for backups, which you can integrate with Proxmox’s backup tools.
    Network Configuration: If using iSCSI over a dedicated 10GbE network, ensure the iSCSI traffic is on a separate VLAN or subnet to isolate it from other Proxmox management traffic.
    Performance Tuning: Both setups will allow you to enable ZFS settings like atime=off, compression=on, and sync=standard for better performance on iSCSI-based VM storage.

Summary

Plain Ubuntu: Ideal if you prefer a minimalist approach with separate storage management outside of Proxmox. This keeps roles separate but requires some manual setup.
    Proxmox VE on Storage Server: Best if you prefer a unified interface for storage and ZFS management and may use the server for other lightweight tasks. It’s easy to set up and manage with Proxmox’s web UI, but requires using an external iSCSI configuration tool.

Both setups can work well in your Proxmox environment. The Proxmox-as-OS option might offer a more streamlined experience since you’re already familiar with it, especially if you want simpler management across all nodes in the cluster.
Du:
will i have to create volumes for each vm and lxc i have and will have in the future outside proxmox? this is not 100% what i want... maybe better make a zvol aof 100% the zfs raid fs and put it as target in pve?
ChatGPT:
ChatGPT

Here's a way to streamline the setup by creating a single, large ZVOL to act as an iSCSI target. Proxmox can then manage the space within this volume using LVM, giving you flexibility and avoiding the need to manually create new ZVOLs for each VM or container.
Simplified Approach: Single Large ZVOL as iSCSI Target Managed by Proxmox

Create a Large ZVOL on the ZFS Pool:
        On your storage server (running either Ubuntu or Proxmox as the base), create a single, large ZVOL that spans most of your ZFS pool capacity.
        For example, if your ZFS pool is omv, you can create a ZVOL named pve_storage using a command like:

zfs create -V 13T omv/pve_storage

This will create a 13TB ZVOL, which Proxmox can treat as a single iSCSI target.

Export the ZVOL as an iSCSI Target:
        Use targetcli or tgt to set up an iSCSI target for the ZVOL (omv/pve_storage).
        Map this ZVOL as a LUN on the iSCSI target, so it can be seen as a single large disk by Proxmox.

Connect Proxmox to the iSCSI Target:
        In Proxmox, go to Datacenter > Storage > Add > iSCSI and add the iSCSI target you just created.
        Provide the IP address of your storage server and the iSCSI target name, then save the configuration.

Format the iSCSI Disk with LVM in Proxmox:
        Once Proxmox detects the iSCSI target, format it with LVM to enable Proxmox to manage storage within that large ZVOL.
        Go to Datacenter > Storage > Add > LVM, and select the iSCSI disk as the base for a new LVM volume group.
        This setup will allow Proxmox to create logical volumes dynamically within the ZVOL-backed LVM group, which will serve as VM disks or container storage.

Use the LVM Storage in Proxmox for VM and LXC Storage:
        Now, in Proxmox, you can select this LVM-based storage as a target for VM and LXC disks.
        Proxmox will handle creating and managing VM and container disks dynamically within the LVM volume group, giving you flexibility similar to a local storage setup.

Benefits of This Approach

Dynamic Storage Allocation: Proxmox will manage individual VM and container disks within the large iSCSI-backed LVM volume group, eliminating the need to pre-create ZVOLs for each VM or container.
    Centralized Storage: By using a single large ZVOL, you centralize management on the storage server, with Proxmox managing VM storage allocation within that large volume.
    Reduced Complexity: You avoid the manual work of creating ZVOLs for each new VM or container, which simplifies maintenance and scaling.

Potential Considerations

Snapshot Limitations: ZFS snapshots at the ZVOL level will snapshot the entire large ZVOL rather than individual VMs. If you need per-VM snapshots, Proxmox’s LVM-based snapshots will be limited compared to ZFS snapshots. However, Proxmox backups and snapshot features on this setup will work as expected.
    Performance Optimization: Monitor the performance of the large ZVOL. ZFS and iSCSI generally handle this well, but adjust settings like recordsize and sync on the ZVOL to optimize for VM workloads.

Summary

This approach balances flexibility and simplicity by using a single ZVOL as an iSCSI target. Proxmox can then manage individual VM and container storage volumes within the LVM layer on this target, effectively turning your storage server into a centralized storage system while keeping Proxmox in control of storage allocation. This setup allows you to expand VM and container storage dynamically without needing to adjust anything on the storage server.
Du:
does my zfs pool has to be empty? how easy can I expand the zvol? eg. i have 10tb, 3 are occupied with my media lib. can i make a 7tb zvol, move my media there and then clear the now freed 3tb and expand the 7tb zvol to the full 10tb available?
ChatGPT:
ChatGPT

Create a 7TB ZVOL:
        You can create a ZVOL of 7TB from your pool without needing to worry about the existing data occupying 3TB of space. ZFS will allocate the required space for the ZVOL from the free space in the pool, which is 7TB in your case.
        Run the following command to create a 7TB ZVOL:

zfs create -V 7T omv/your_zvol_name

This command creates a 7TB virtual block device (your_zvol_name) under your ZFS pool (omv).

Move Your Data to the New ZVOL:

You can then move your media library or data from your current ZFS dataset (which is taking up 3TB) to the newly created ZVOL.
    You can use rsync or a similar tool to transfer data from one dataset to another, making sure you preserve permissions and metadata:

rsync -avh /path/to/old/dataset/ /path/to/your_zvol_mountpoint/

Delete the Old Data:

Once the data is safely moved to the new ZVOL, you can delete the old dataset that’s taking up the 3TB. This frees up the 3TB of space, allowing it to be reclaimed in the pool.

zfs destroy omv/old_dataset

Expand the ZVOL to Use the Full 10TB:

Now that you have freed up the 3TB by moving your media library and deleting the old dataset, you can expand the ZVOL to use the full 10TB of available space.
    To expand the ZVOL, use the following command:

zfs set volsize=10T omv/your_zvol_name

This will resize the ZVOL to occupy all 10TB of space in your pool.

Important Notes

ZFS Space Management: ZFS is quite flexible with its space allocation. It doesn’t pre-allocate the entire space when you create a ZVOL; it dynamically uses space as data is written. The ZVOL will grow in size as data is written to it, up to the maximum size you specify.

Expanding ZVOLs: Expanding a ZVOL is simple and doesn’t require you to move data around or destroy any existing data. As long as the ZFS pool has free space, expanding a ZVOL is a straightforward operation. When you run the zfs set volsize=10T command, ZFS will resize the ZVOL, and the additional space will be available for use.

Data Integrity: Always ensure you have a backup of your important data before performing any operations like resizing or moving data. While ZFS is highly reliable, it’s always best practice to have backups.

Performance Considerations: If you’re moving a large amount of data, ensure you have good network or disk throughput to minimize downtime. ZFS provides excellent tools like snapshots, which can allow you to take a point-in-time backup before moving data.

Conclusion

No, your ZFS pool doesn’t need to be empty to create and expand a ZVOL. You can create a 7TB ZVOL, move your data, and then expand it to use the full available space in your pool without issue. ZFS makes this process relatively easy with its dynamic volume management, and you can manage space efficiently as long as you have free space in the pool. Just make sure to safely move and verify your data before expanding the ZVOL.
Du:
will there be actual io when i shift the data? 3tb read and write are timeconsuming and wear the disks
ChatGPT:
ChatGPT

However, there are ways to minimize the impact of these operations, and I'll outline a few strategies you can use:
1. Use rsync with Optimizations:

rsync is a powerful tool for data migration because it can be optimized to minimize disk I/O. You can use it with specific flags to optimize the read and write operations:

--inplace: This option allows rsync to write to the target directly rather than creating temporary files, which reduces the additional writes needed.
    --dry-run: Before actually moving the data, run rsync with the --dry-run flag to see how much data will be moved and make sure everything is set up correctly. This is a way to avoid surprises.
    --bwlimit: If you want to limit the rate at which rsync performs the transfer to reduce load on your system, you can use the --bwlimit option to throttle the bandwidth (e.g., --bwlimit=100M to limit the speed to 100MB/s).

Example rsync command for minimal I/O:

rsync -avh --inplace --bwlimit=100M /path/to/source/ /path/to/destination/

This command will move the data from your source to your destination, with minimal extra I/O overhead and bandwidth control.
2. Use ZFS Snapshots and Clones (Optional):

If you're running this migration on a ZFS-backed storage system, one approach to reduce I/O and risk of wear is to use ZFS snapshots and clones:

Snapshot the Source Dataset: Before migrating the data, you can create a snapshot of the original dataset. This creates a read-only point-in-time copy without additional disk writes.

zfs snapshot omv/source_dataset@snapshot_name

zfs clone omv/source_dataset@snapshot_name omv/clone_for_move

Move Data from Clone: You can now move data from the clone to the target ZVOL with rsync or a similar tool. After the move, you can destroy the clone.

Cleanup: Once the data is safely transferred, you can destroy the clone and snapshot:

zfs destroy omv/source_dataset@snapshot_name
    zfs destroy omv/clone_for_move

This method doesn’t require physical copying of the data and allows you to migrate without causing significant I/O to the original data.
3. Schedule Transfers During Off-Peak Hours:

Example for sending and receiving:

zfs snapshot omv/source_dataset@snapshot_name
zfs send omv/source_dataset@snapshot_name | zfs receive omv/target_dataset

This operation may be faster than a full rsync and could be a more efficient way to move the data without putting as much wear on the disks.
5. Move Data in Phases:

Rather than moving the entire 3TB of data all at once, you could break the transfer into smaller, more manageable chunks. This reduces the load on the disks at any given time. For example:

Move a few hundred gigabytes at a time.
    Run multiple smaller rsync commands sequentially or in parallel.

This might take longer in total but will help distribute the load across the migration process and prevent the system from being overwhelmed.
6. Monitor Disk Health and Wear:

You can check SMART status with:

smartctl -a /dev/sdX

Also, monitor the I/O load and disk usage during the transfer using iostat, zpool iostat, or other system monitoring tools to make sure that the system isn't under heavy load.
Conclusion

Yes, moving 3TB of data will result in I/O operations (reads and writes) that will take time and can contribute to wear on the disks, but there are ways to minimize the impact. Using rsync with optimizations, leveraging ZFS snapshots and clones, scheduling the migration during off-peak hours, or even using zfs send/receive can all help reduce the amount of actual disk I/O required and spread the load over time. Be sure to monitor disk health throughout the process, and if possible, break the transfer into smaller steps to further minimize the impact.
Du:
when i finally have my masss torage as iscsi available in pve? will i have the base os of my vm and lxc on my ssd and only mass storage on hdd provided as extra disk to the guests? that way i have the os on fast ssd and the less volatile data on hdd
ChatGPT:
ChatGPT

Here's a more detailed breakdown of how you can set this up:
1. Install the Base OS of VMs and LXCs on SSD:

VMs: When you create a virtual machine in Proxmox, you can specify the location of the virtual disks. In this case, you would want to store the VM base disk on your fast SSD.
        During VM creation, choose the SSD storage as the target for the virtual disk(s).
        This ensures that the operating system and any fast-access data (like application files or databases) will benefit from the speed of the SSD.
    LXCs: Similarly, when creating LXC containers, you can configure the storage location for their root filesystems. Store these root filesystems on the SSD for improved performance.
        In Proxmox, this would involve selecting a storage backend (like local SSD) for the LXC container.

2. Attach Mass Storage (iSCSI) to VMs/LXCs:

You can use iSCSI to provide extra storage (like your 10TB ZFS pool or other storage volumes) to your VMs or LXCs as additional virtual disks.
    Once your iSCSI target (your OpenMediaVault server or the Proxmox host with ZFS and iSCSI) is available and configured:
        For VMs: You can add the iSCSI LUN (Logical Unit Number) as a virtual disk to the VM. The disk can be formatted and mounted inside the VM to store less-volatile data, such as backups, media files, or large datasets.
        For LXCs: You can similarly mount iSCSI storage inside an LXC container to store large data volumes.

3. Steps to Set Up Mass Storage via iSCSI for VMs/LXCs:

On Proxmox (Host) Side:
        Make sure the iSCSI initiator on the Proxmox host is configured to connect to the iSCSI target.
        Use iscsiadm or Proxmox’s web interface to connect to the iSCSI target and present the LUN to the Proxmox host.
        Create a storage definition for the iSCSI LUN in Proxmox (either via the GUI or the /etc/pve/storage.cfg file). This allows you to use the iSCSI storage as a backend for VM disks or as additional storage for LXCs.

Example configuration for Proxmox storage (/etc/pve/storage.cfg):

iscsi: iscsi-storage
        portal xxx.xxx.xxx.xxx
        target iqn.1993-08.org.debian:01:abcdef1234
        username your-iscsi-user
        password your-iscsi-password

On the VM Side:
        Once the iSCSI storage is available on Proxmox, you can add the iSCSI LUN as a new disk to your VM.
        When configuring the VM, in the "Hardware" section, you would add a new disk, selecting the iSCSI storage you configured earlier as the disk target.
        Format this disk within the VM and mount it where appropriate for your data.

On the LXC Side:
        For LXCs, you can mount the iSCSI disk as a block device directly or use a shared directory setup.
        Use a mount command inside the LXC or define the mount in the LXC config file to make the iSCSI volume accessible.

4. Advantages of This Setup:

Performance: By keeping the base OS and application data on fast SSD storage, your VMs and LXCs will benefit from the performance advantages of SSDs, such as faster boot times and lower latency for OS-level operations and applications.
    Separation of Data: Storing less-volatile data (like media, large files, or backups) on HDDs via iSCSI provides you with ample storage space at a lower cost, without sacrificing SSD performance for the base OS and critical data.
    Flexibility: If you need to expand storage, you can do so on the iSCSI target without impacting the performance of your SSD-based base OS or VMs.
    Scalability: Your storage setup can grow by simply adding more iSCSI targets or expanding the ZFS pool without affecting the underlying VM and LXC setups.

5. Considerations:

Network Bandwidth: Since you're using 10GbE for networking, ensure that your iSCSI traffic can fully utilize this bandwidth. iSCSI over a 10GbE network will allow for high-speed access to your mass storage, but make sure that the network is configured correctly and isn’t congested.
    IO Performance: While SSDs provide excellent performance, HDDs are much slower, especially for random access. Ensure that the mass storage on the HDDs via iSCSI is used appropriately for workloads that don't require high IOPS (e.g., media storage, backups, archives).
    ZFS Considerations: ZFS is a great choice for managing storage with redundancy and data integrity. However, if your mass storage is going to handle many writes (such as large file servers), you may need to ensure that your ZFS setup is optimized for performance (e.g., proper use of compression, deduplication, and caching) to minimize overhead on the storage system.

Conclusion