Re: about the xfs performance

Emmanuel Florac
2016-04-11T16:10:03Z

Le Mon, 11 Apr 2016 22:14:06 +0800
Songbo Wang <hack.coo@gmail.com> écrivait:

> mkfs: mkfs.xfs /dev/hioa2 -f -n size=64k -i size=512 -d
> agcount=40 -l size=1024m.
> mount: mount /dev/hioa2 /mnt/ -t xfs -o
> rw,noexec,nodev,noatime,nodiratime,nobarrier,discard,inode64,logbsize=256k,delaylog
> I use the following command to test iops: fio -ioengine=libaio -bs=4k
> -direct=1 -thread -rw=randwrite -size=50G -filename=/mnt/test
> -name="EBS 4KB randwrite test" -iodepth=64 -runtime=60
> The results is normal at the beginning which is about 210k±，but some
> seconds later, the results down to 19k±.

You should first try default mkfs settings, with default mount options.
Normally mkfs.xfs should initiate a TRIM on the SSD, therefore
performance should remain predictable.

What model of SSD card are you using? With an HGST NVMe SN1x0 I've got
very consistent results (no degradation with time).

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