[pve-devel] ceph firefly in pve repos
Alexandre DERUMIER
aderumier at odiso.com
Fri Sep 12 06:42:32 CEST 2014
>>That is about 250 IOPS?
Yes, I got same result with fio and --sync=1
crucial m550
------------
#fio --filename=/dev/sdb --direct=1 --rw=write --bs=4k --numjobs=2 --group_reporting --invalidate=0 --name=ab --sync=1
bw=1249.9KB/s, iops=312
intel s3500
-----------
fio --filename=/dev/sdb --direct=1 --rw=write --bs=4k --numjobs=2 --group_reporting --invalidate=0 --name=ab --sync=1
#bw=41794KB/s, iops=10448
ok, so 30x faster.
I have read on the net some benchmark , and seem that the cacheflush is really slow on theses crucial
Now, same benchmark, but with stefan kernel patch + echo temporary write through
crucial m550
------------
#fio --filename=/dev/sdb --direct=1 --rw=write --bs=4k --numjobs=2 --group_reporting --invalidate=0 --name=ab --sync=1
bw=177575KB/s, iops=44393
:)
This sound like "zfs_nocacheflush" option in zfs. zfs recommand to enable it only with supercap ssds.
----- Mail original -----
De: "Dietmar Maurer" <dietmar at proxmox.com>
À: "Alexandre DERUMIER" <aderumier at odiso.com>
Cc: pve-devel at pve.proxmox.com
Envoyé: Jeudi 11 Septembre 2014 08:40:35
Objet: RE: [pve-devel] ceph firefly in pve repos
> # dd if=rand.file of=/dev/sdb bs=4k count=65536 oflag=dsync,direct
> ^C17228+0 enregistrements lus
> 17228+0 enregistrements écrits
> 70565888 octets (71 MB) copiés, 70,4098 s, 1,0 MB/s
That is about 250 IOPS?
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