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Bug 1103845 - glusterfs backend does not support discard (libvirt)
Summary: glusterfs backend does not support discard (libvirt)
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: libvirt
Version: 7.1
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: ---
Assignee: Peter Krempa
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On: 1055487 1136534
Blocks: GlusterThinProvisioning
TreeView+ depends on / blocked
 
Reported: 2014-06-02 17:51 UTC by Hai Huang
Modified: 2016-11-03 18:09 UTC (History)
14 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 1037503
Environment:
Last Closed: 2016-11-03 18:09:24 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2016:2577 0 normal SHIPPED_LIVE Moderate: libvirt security, bug fix, and enhancement update 2016-11-03 12:07:06 UTC

Comment 1 Peter Krempa 2014-06-03 06:52:15 UTC 
This works with libvirt with the following configuration:

    <disk type='network' device='disk'>
      <driver name='qemu' type='qcow2' discard='unmap'/>  <-- important
      <source protocol='gluster' name='gv0/img7'>
        <host name='gluster-node-1'/>
      </source>
      <target dev='sda' bus='scsi'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>


In guest:
# cat /sys/bus/scsi/devices/target2:0:0/2:0:0:0/scsi_disk/2:0:0:0/provisioning_mode
unmap

Setting test-only keyword.
Comment 2 Yang Yang 2014-11-07 07:52:53 UTC 
Verified on 
libvirt-1.2.8-5.el7 
qemu-kvm-rhev-2.1.2-4.el7.x86_64
qemu-kvm-1.5.3-76.el7

test matrix:
qemu: qemu-kvm-rhev, qemu-kvm
host fs type: ext4, xfs
disk format: raw, qcow2
disk interface: scsi, ide, sata, virtio
disk fs type: ext4, xfs


Steps:
mount the gluster server to your host

mount -t glusterfs $ip:gluster-vol1 -o direct-io-mode=1 /tmp/gluster

1. Boot guest with the following xml

<disk type='network' device='disk'>
<driver name='qemu' type='qcow2' cache='none'/>
<source protocol='gluster' name='gluster-vol1/rhel7-qcow2.img'>
<host name='$ip'/>
</source>
<backingStore/>
<target dev='vda' bus='virtio'/>
</disk>
<disk type='network' device='disk'>
<driver name='qemu' type='qcow2' discard='unmap'/>
<source protocol='gluster' name='gluster-vol1/t-qcow2.img'>
<host name='$ip'/>
</source>
<backingStore/>
<target dev='sda' bus='scsi'/>
</disk>
<disk type='network' device='disk'>
<driver name='qemu' type='qcow2' discard='ignore'/>
<source protocol='gluster' name='gluster-vol1/y-qcow2.img'>
<host name='$ip'/>
</source>
<backingStore/>
<target dev='sdb' bus='scsi'/>
</disk>
<disk type='network' device='disk'>
<driver name='qemu' type='qcow2'/>
<source protocol='gluster' name='gluster-vol1/z-qcow2.img'>
<host name='$ip'/>
</source>
<backingStore/>
<target dev='sdc' bus='scsi'/>
</disk>

2. check qemu line
# ps -ef|grep qemu | grep discard

-drive file=gluster://$ip/gluster-vol1/rhel7-qcow2.img,if=none,id=drive-virtio-disk0,format=qcow2,cache=none -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x9,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -drive file=gluster://$ip/gluster-vol1/t-qcow2.img,if=none,id=drive-scsi0-0-0-0,format=qcow2,discard=unmap -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0 -drive file=gluster://$ip/gluster-vol1/y-qcow2.img,if=none,id=drive-scsi0-0-0-1,format=qcow2,discard=ignore -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi0-0-0-1,id=scsi0-0-0-1 -drive file=gluster://$ip/gluster-vol1/z-qcow2.img,if=none,id=drive-scsi0-0-0-2,format=qcow2 -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=2,drive=drive-scsi0-0-0-2,id=scsi0-0-0-2 -netdev tap,fd=179,id=hostnet0,vhost=on,vhostfd=180 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:8f:13:eb,bus=pci.0,addr=0x3 -chardev pty,id=charserial0

3. guest ]# lsscsi
[2:0:0:0] disk QEMU QEMU HARDDISK 2.1. /dev/sda
[2:0:0:1] disk QEMU QEMU HARDDISK 2.1. /dev/sdb

[2:0:0:2] disk QEMU QEMU HARDDISK 2.1. /dev/sdc

guest ]# cat /sys/bus/scsi/devices/target2\:0\:0/2\:0\:0\:0/scsi_disk/2\:0\:0\:0/provisioning_mode
unmap

4. In guest, make ext4 filesystem on sda, sdb
#mkfs.ext4 /dev/sda
#mkfs.ext4 /dev/sdb

#mkfs.ext4 /dev/sdc

5. In host, check the disk block

# stat t-qcow2.img
  File: ‘t-qcow2.img’
  Size: 35061760      Blocks: 68360      IO Block: 131072 regular file

# stat y-qcow2.img
  File: ‘y-qcow2.img’
  Size: 35061760      Blocks: 68368      IO Block: 131072 regular file

# stat z-qcow2.img
  File: ‘z-qcow2.img’
  Size: 35061760      Blocks: 68368      IO Block: 131072 regular file

6. In guest, mount sda and sdb
#mount /dev/sda /sda
#mount /dev/sdb /sdb

#mount /dev/sdc /sdc

7. In guest, dd a big file
dd if=/dev/urandom of=/sda/file bs=1M count=300 && sync
dd if=/dev/urandom of=/sdb/file bs=1M count=300 && sync

dd if=/dev/urandom of=/sdc/file bs=1M count=300 && sync

8. In host, check the disk block

# stat t-qcow2.img
  File: ‘t-qcow2.img’
  Size: 350093312     Blocks: 683664     IO Block: 131072 regular file

# stat y-qcow2.img
  File: ‘y-qcow2.img’
  Size: 350093312     Blocks: 683664     IO Block: 131072 regular file

# stat z-qcow2.img
  File: ‘z-qcow2.img’
  Size: 350093312     Blocks: 683664     IO Block: 131072 regular file

9. In guest, remove the file
#rm /sda/file -f && sync
#rm /sdb/file -f && sync

#rm /sdc/file -f && sync

#fstrim /sda

#fstrim /sdb

#fstrim /sdc

10. In host, check the disk block

# stat t-qcow2.img
  File: ‘t-qcow2.img’
  Size: 350093312     Blocks: 683664     IO Block: 131072 regular file

# stat y-qcow2.img
  File: ‘y-qcow2.img’
  Size: 350093312     Blocks: 683664     IO Block: 131072 regular file

# stat z-qcow2.img
  File: ‘z-qcow2.img’
  Size: 350093312     Blocks: 683664     IO Block: 131072 regular file
Comment 3 Yang Yang 2014-12-04 05:29:25 UTC 
Per comment #5 in qemu bug 1136534, mark it as failedQA. Will verify it after qemu bug 1136534 fixed.
Comment 5 yisun 2015-08-28 05:52:50 UTC 
bz 1055487 and bz 1136534 have been moved to rhel7.3.0, could you pls move this one to 7.3.0? thx
Comment 7 yisun 2016-08-10 11:54:18 UTC 
Verified with pkgs:
libvirt-2.0.0-4.el7.x86_64
qemu-kvm-rhev-2.6.0-17.el7.x86_64
glusterfs-server-3.7.9-11.el7rhgs.x86_64




HOST# virsh dumpxml virtlab_test 
...
    <disk type='network' device='disk'>
      <driver name='qemu' type='qcow2' discard='unmap'/>
      <source protocol='gluster' name='gluster-vol1/qcow2.img'>
        <host name='$IP'/>
      </source>
      <target dev='sda' bus='scsi'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <disk type='network' device='disk'>
      <driver name='qemu' type='raw' cache='none' discard='unmap'/>
      <source protocol='gluster' name='gluster-vol1/raw.img'>
        <host name='$IP'/>
      </source>
      <target dev='sdb' bus='scsi'/>
      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
    </disk>
...

HOST# virsh start virtlab_test
Domain virtlab_test started

HOST# ps -ef | grep qemu | grep unmap
qemu      7090     1  4 19:26 ?        00:00:08 /usr/libexec/qemu-kvm -name guest=virtlab_test, .... -drive file=gluster://10.66.5.82/gluster-vol1/qcow2.img,format=qcow2,if=none,id=drive-scsi0-0-0-0,discard=unmap -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0 -drive file=gluster://10.66.5.82/gluster-vol1/raw.img,format=raw,if=none,id=drive-scsi0-0-0-1,cache=none,discard=unmap ....


GLUSTER# stat raw.img 
  File: ‘raw.img’
  Size: 1073741824	Blocks: 8          IO Block: 4096   regular file

GLUSTER# stat qcow2.img 
  File: ‘qcow2.img’
  Size: 197120    	Blocks: 400        IO Block: 4096   regular file


GUEST# lsscsi
[2:0:0:0]    disk    QEMU     QEMU HARDDISK    2.5+  /dev/sda 
[2:0:0:1]    disk    QEMU     QEMU HARDDISK    2.5+  /dev/sdb 

GUEST# cat /sys/bus/scsi/devices/target2\:0\:0/2\:0\:0\:0/scsi_disk/2\:0\:0\:0/provisioning_mode 
unmap

GUEST# cat /sys/bus/scsi/devices/target2\:0\:0/2\:0\:0\:1/scsi_disk/2\:0\:0\:1/provisioning_mode 
unmap

GUEST# mkfs.ext4 /dev/sda
GUEST# mkfs.ext4 /dev/sdb



GUEST# mkdir /sda
GUEST# mkdir /sdb
GUEST# mount /dev/sda /sda
GUEST# mount /dev/sdb /sdb

GLUSTER# stat raw.img 
  File: ‘raw.img’
  Size: 1073741824	Blocks: 66352      IO Block: 4096   regular file

GLUSTER# stat qcow2.img 
  File: ‘qcow2.img’
  Size: 559546368 	Blocks: 67736      IO Block: 4096   regular file





GUEST# dd if=/dev/zero of=/sda/file bs=1M count=500
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 4.76586 s, 110 MB/s

GUEST# dd if=/dev/zero of=/sdb/file bs=1M count=500
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 6.36393 s, 82.4 MB/s


GLUSTER# stat raw.img 
  File: ‘raw.img’
  Size: 1073741824	Blocks: 1123136    IO Block: 4096   regular file

GLUSTER# stat qcow2.img 
  File: ‘qcow2.img’
  Size: 559546368 	Blocks: 1164176    IO Block: 4096   regular file



GUEST# rm /sda/file -f
GUEST# fstrim /sda
GUEST# rm /sdb/file -f
GUEST# fstrim /sdb

GLUSTER# stat raw.img 
  File: ‘raw.img’
  Size: 1073741824	Blocks: 344784     IO Block: 4096   regular file


GLUSTER# stat qcow2.img 
  File: ‘qcow2.img’
  Size: 559546368 	Blocks: 68624      IO Block: 4096   regular file
Comment 9 errata-xmlrpc 2016-11-03 18:09:24 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2016-2577.html
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