[Rdo-list] cinder speed (slow nova?)

[Dmitry Makovey]

Hi everybody,

using RDO IceHouse packages I've set up an infrastructure atop of
RHEL6.6 and am seeing a very unpleasant performance for the storage.

I've done some testing and here's what I get from the same storage: but
different access points:

cinder-volume # dd if=/dev/zero of=baloon bs=1048576 count=200
200+0 records in
200+0 records out
209715200 bytes (210 MB) copied, 0.162997 s, 1.3 GB/s

nova-compute # dd if=/dev/zero of=baloon bs=1048576 count=200
200+0 records in
200+0 records out
209715200 bytes (210 MB) copied, 0.167905 s, 1.2 GB/s

instance # dd if=/dev/zero of=baloon bs=1048576 count=200
200+0 records in
200+0 records out
209715200 bytes (210 MB) copied, 10.064 s, 20.8 MB/s

A bit of explanation: in above scenario I have created LV on
cinder-node, then mounted it locally and ran command for
"cinder-volume". Created an iSCSI target, mounted it on nova-compute,
and ran command there. Then, via cinder created storage volume, booted
the OS off it, and ran test from within it... Results are just
miserable. going from 1.2G/s down to 20M/s seems to be a big
degradation. What should I look for? I have also tried running the same
command within our RHEL KVM instance and got great performance.

I have checked under /var/lib/nova/instances/* and libvirt.xml seems to
indicate that virtio is being employed:

    <disk type="block" device="disk">
      <driver name="qemu" type="raw" cache="none"/>
      <source
dev="/dev/disk/by-path/ip-192.168.46.18:3260-iscsi-iqn.2010-10.org.openstack:volume-955b25eb-bb48-43c3-a14d-222c9e8c7019-lun-1"/>
      <target bus="virtio" dev="vda"/>
      <serial>955b25eb-bb48-43c3-a14d-222c9e8c7019</serial>
    </disk>

guest used - is rhel-guest-image-6.6-20140926.0.x86_64.qcow2 downloaded
off RH site.

-- 
Dmitry Makovey
Web Systems Administrator
Athabasca University
(780) 675-6245
---
Confidence is what you have before you understand the problem
    Woody Allen

When in trouble when in doubt run in circles scream and shout
     http://www.wordwizard.com/phpbb3/viewtopic.php?f=16&t=19330

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