[sheepdog-users] cache performance test

Valerio Pachera sirio81 at gmail.com
Wed Jul 17 17:36:59 CEST 2013

Here I am with a new performance test with Sheepdog 0.6.0_127_g085568a.
I don't understand the reason, but write speed with cache enabled is
the same as without cache.

The host where I'm running the guest has this configuration:
  sheep -w size=20000 /mnt/sheep/meta/,/mnt/sheep/dsk02

/dev/sda3 on /mnt/sheep/meta type xfs (rw,relatime,attr2,delaylog,noquota)
/dev/sdb1 on /mnt/sheep/dsk02 type xfs (rw,relatime,attr2,delaylog,noquota)

sda is and ssd disk!

The guest
qemu-system-x86_64 -name backup -enable-kvm -drive
file=sheepdog:backup,cache=writeback -drive
file=sheepdog:backup_data,cache=writeback ...

dd if=/dev/zero of=c1 bs=1M count=512 oflag=sync
512+0 record dentro
512+0 record fuori
536870912 byte (537 MB) copiati, 63,3792 s, 8,5 MB/s

I'm writing into sheepdog:backup_data (1T), also formatted with xfs.

The other two hosts have almost the same configuration:
  sheep -w size=20000 /mnt/sheep/dsk01,/mnt/sheep/dsk01/obj,/mnt/sheep/dsk02

/dev/vg00/sheepdog      /mnt/sheep/dsk01        xfs
defaults,noatime        0       2
/dev/sdb1       /mnt/sheep/dsk02       xfs     defaults,noatime        0       2

No ssd here.
The performance is exactly the same.

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