ZFS SSD Stripe low iops, High IO Delay

[user8923428934]

Hi,

We are currently running 2 SSD ZFS stripe pools one with 3X250gb drives (let's call it Pool1) and the other with 2X500gb ssds (Pool2). The SSDs are consumer grade ones but they should still deliver at least 8000 to 90000 iops according to their documentation. (Crucial mx 500. Pool2). The Pool1 has 3 different SSDs some older than others and some with more iops than others. still the slowest ssd should still deliver 10000 iops and the others aroung 80000. However when I then try to run 2 VMs on Each pool (windows Server 2016 with 8gb ram each and 4 vcpus) the IO delay spike to ca 50% and makes the vms unusable. Am I missing something something here? shouldn't the performance be a lot higher with striped ssds? I know that you shouldn't use striped pools because of now redundancy but in this case that isnt't important. the vms just need to be fast.

So if I but these numbers into a raid calculator (I know that those numbers are only theoretical) i should get at least 120000 iops on pool1 and 150000 on pool2.
And the strange thing is that we already used these exact ssds one by one in a VMware server (no raid or anything just 1 ssd as datastore) and the same VMs where totally usable.

Hardware
Dell power edge r530
1X xeon 2680v4
32gb ddr4 RAM
500gb HDD boot drive (cloud the slow boot drive have an effect on the Pools performance?)

Thanks in advance

 

[ness1602]

Consumer drives are really bad for enterprise load.

 

[LnxBil]

Consumer drives are really bad for enterprise load.

for any loads that is not idling.

 

[user8923428934]

thanks for the answer. I know that they are not intended for enterprise use, But it just doesn't make sense to me that these same drives once performed better when they where in a single drive zfs config and now as they are in a stripe pool they are completely unusable.

Does anyone know what the reason could be?

 

[Dunuin]

Also never compare new empty drives and filled up drives. Consumer SSDs get really slow when filled up because they don't got a big spare NAND area like enterprise SSDs. Were both pools filled up to the same percentage?

 

[Falk R.]

You have 4 VMs with 8GB RAM on a System With 32GB?
Its possible, that Swapping slow down the System?