[pve-devel] [PATCH v4 manager] HDEdit: check iothread by default and move it from advanced section

Matthias Heiserer m.heiserer at proxmox.com
Mon Jun 13 11:59:24 CEST 2022

On 10.06.2022 11:20, Fabian Ebner wrote:
> Am 27.05.22 um 13:48 schrieb Matthias Heiserer:
>> Existing disks are not changed by this.
>> Especially in benchmarks, iothreads significantly improve IO performance.
>> Signed-off-by: Matthias Heiserer <m.heiserer at proxmox.com>
> Reviewed-by: Fabian Ebner <f.ebner at proxmox.com>
>> ---
>> Changes from v3:
>> * remove automatically switching to/from SCSI single when iothread is (un)checked
>> * iothread will be initially set on
>> * changing the controller to something other than SCSI single and then back to
>>    SCSI single will enable iothread for all SCSI disks.
> I like this version much more. We could still add validation/warning to
> the checkbox, but IMHO not a big deal with the new default and improved
> warning upon VM start. Just wondering if we should enable iothread by
> default for virtio disks too, or is the performance improvement not as
> relevant there?
Okay great, then I won't change the UI in v5.

Just did a very quick test and on my machine it seems to make read 
benchmarks faster, but write is slightly slower. Will enable it in v5.

fio --ioengine=libaio --direct=1 --sync=1 --rw=read --bs=4k --numjobs=1 
--iodepth=1 --runtime=60 --time_based --name seq_read --filename=/dev/vdb

With iothread:
read: IOPS=27.1k, BW=106MiB/s
write: IOPS=707, BW=2831KiB/s

Without iothread:
read: IOPS=13.4k, BW=52.5MiB/s
write: IOPS=787, BW=3150KiB/s

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