Freenas iscsi target for hyper-v host - backup necessary?

[BabaJega]

Hello all,

I am planning on using my Freenas box as iscsi target for my hyper-v host to store all my VMs on it (500GB SSD Stripe Set in Freenas).

The freenas box is replicated to a freenas VM every 3 hours (yes, I am using pci passthrough (DDA in microsoft language) with a IBM ServeRaid M1015 flashed to IT mode).

1. Is this scenario a good idea or am I doing terrible mistakes by even thinking about it?
2. Is it necessary to use a backup software (like veeam) for my VMs or is the zfs pool plus replication to a different freenas VM enough?
3. Would turning on deduplication ONLY ON THE 500gb STRIPESET be a good idea? Would my box be able to handle the workload?

Thanks in advance for the input!

Specs:

Freenas Box:
- Xeon E3 1220 V2
- 32 GB ECC Ram
- 6x 4TB WD Red (Raid Z2)
- 2x 500gb SSD (Stripe Set)
- Mellanox ConnectX-3 (DAC to Hyper-V)
- IBM ServeRaid M1015

Hyper-V Host:
- Ryzen 7 1700x
- 64GB ECC Ram (Asrock AB350 Pro4 supports ECC Ram)
- Some SSDs
- Mellanox ConnectX-3 (DAC to Freenas)
- IBM ServeRaid M1015

 

[JaimieV]

1 - The stripe set idea is bad and you should feel bad. If you need the speed, get the budget for two 1TB m.2 PCIe drives and mirror them. The backup being virtual seems reasonable, given that it is solely for backup. There’s a post in the stickies of the “new to freenas” forum about how not to hurt yourself running FreeNAS in a vm, go find it. Also look at the iscsi stickies in the “sharing” forum.
2 - Outside my sphere, sorry. Probably ask in the sharing or bhyve forums.
3 - Don’t use dedupe. What effect are you expecting? There may be a sane way to achieve it. Adding ram will always help.

 

[BabaJega]

Hello and thank you for trying to answer my questions.
Unfortunately, the M.2 SSDs are not an option since I barely have any PCIe lanes left (about 3 I think) and there are no M.2 slots on the mainboard of my nas since it is a bit outdated. The stripe set wont be an issue if the backup works as intended.

But my main question was: Will the VMs work properly if I take a snapshot in freenas, roll it back and fire them up again?
I guess the only option now is to test it myself...

 

[blanchet]

Facts to consider:

• Before triggering a ZFS snapshot, you have to poweroff the VMs or take a snapshot in the hypervisor, otherwise the backups are not crash-consistent. It is the reason why FreeNAS has a special vmware-snapshot mode. (that obviously does not work with Hyper-V).
• Restoring a VM from a ZFS backup without a third-party tool is not very convenient.

Therefore I recommend to use a third-party tool to backup and restore VM. There are many tools on the market, but I strongly recommend Veeam Backup & Replication. The Community Edition is free to backup up to 10 VMs.

You can run the Veeam on any Windows computer but it is more convenient to run it on dedicated virtual machine either on your Hyper-V server or directly on your FreeNAS (in bhyve).

You may be also interested by Veeam One Community Edition to monitor your VMs.

 

[BabaJega]

Thank you for the answer. I will use Veeam then.

 

[garm]

The stripe set won't be an issue if the backup works as intended.

False, when you get data corruption ZFS will have no way of correcting it. If you don’t notice it before the next backup cycle there is a non-zero chance of you backing up the corruption and potential poisoning your backup (talking from experience). If the data is of any value, you need redundancy throughout the whole chain..