Mirror configuration performance question

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I'm wondering what the best configuration for performance is: Dual mirrors (one for the OS and one for the VMs) or single mirror (OS and VMs) with a SLOG? Would be using a H200 in IT mode. Disks would all be Intel D3-4610 series.

I'm currently using Samsung 860 Evos in a single mirror with PVE and VMs installed to the same mirror and the performance isn't great:

root@pve:~# pveperf
CPU BOGOMIPS:      76645.56
REGEX/SECOND:      2828253
HD SIZE:           413.52 GB (rpool/ROOT/pve-1)
FSYNCS/SECOND:     357.72
DNS EXT:           32.83 ms
DNS INT:           15.32 ms (localdomain)

Just wondering if adding better drives and splitting up into twin mirrors would help things along.

 

[LnxBil]

splitting up into twin mirrors would help things along.

Given 4 disks: two pools with one vdev each is always slower than one pool with two vdevs, as the load is spread over multiple vdevs. You also don't need so much space (its own pool) for the OS, as PVE uses only a few GB. Best is for performance and space utilization to use one pool with multiple vdevs. Downside is that you cannot reinstall the OS without destroying everything

 

[biggen]

Given 4 disks: two pools with one vdev each is always slower than one pool with two vdevs, as the load is spread over multiple vdevs. You also don't need so much space (its own pool) for the OS, as PVE uses only a few GB. Best is for performance and space utilization to use one pool with multiple vdevs. Downside is that you cannot reinstall the OS without destroying everything

Thanks for this!

I ended up going with a single pool with one mirrored vdev for simplicity (OS and VMs all on one pool). My fsync/second are way better. I'm now around 5500 fsync/s using these Intel D3-4610 drives. I also decided to go with an LSI HBA and move off the motherboard SATA ports.

I don't know what helped the speed increase more, the HBA or the new drives but I'm very happy with the performance now.