Storage recommendation for Windows guest

[user8923428934]

Hi,

We are currently planning our new software test server. Our requirements are to run at least 10 -15 windows 10/11 Vms in parallel. they should all have an "acceptable" performance when working on them

our planned setup looks like this.
2x 14core intel xeon v4
128gb ddr4 ram
4x 1tb m.2 NVME SSD Zfs RAID 10.
Iops per SSD should be 400.000 to 500.000 according to manufacturer.

so in theory we should get between 800.000 to 1.000.000 iops on this zfs pool right?
How much do such numbers differ in reality and how many iops can you on average count in for single VM?
could this Layout work for at least 10 VMs or maybe even more. 15? 20?
Is ZFS RAID 10 even the best layout for this setup? as far as I know Raidz1 to Raidz3 only improves on Read and not Write performance (which is obviously pretty important with this amount of VMs)
How much does more RAM imact zfs performance. Does it make sense to get for example 192 Gb of RAM even though VMs only need 120 and the rest is for arc cache?

Thanks for your inputs

 

[LnxBil]

4x 1tb m.2 NVME SSD Zfs RAID 10.

Does you mobo have 4 slots or do you use an adapter card?

have an "acceptable" performance

What does that mean? e.g. without GPU passthrough, you will not have a good game or video editing experience. Browsing the web is also not so fun without hardware acceleration for video or just simple gifs.

How much does more RAM imact zfs performance. Does it make sense to get for example 192 Gb of RAM even though VMs only need 120 and the rest is for arc cache?

More RAM is always better and enough RAM for ZFS is also always good.

 

[user8923428934]

thanks for the answer.

no i am going to use 2 supermicrto aoc adapter cards. I don't plan on doing any graphically intensive workload on these machines just software testing so GPU performance isn't important for us its more like that these machines are responsive. so you don't need to wait 10-15 seconds when for example opening the explorer or something.

Yes I think so too that more ram is always better but will the additional ca.70 Gb for ZFS have a significant effect.?

what about the IOPS of the storage array. is it enough for our workload?

 

[Dunuin]

Its by the way not recommended to use ZFS with cosumer/prosumer SSDs. And there are barely any enterprise M.2 SSDs because those professional SSDs usually then will use other more suitable NVMe formats like U.2.
Check the ZFS Benchmark Paper: https://www.proxmox.com/de/downloads/item/proxmox-ve-zfs-benchmark-2020
So depending on your workload you can be happy to get a feq hundreds IOPS (for example when using sync writes) when using consumer SSDs. Don't think you will really see those advertised 400k-500k IOPS