Add blockcommit support

[dguerri]

Needs to be tested

[AJRepo]

Two issues:

1. The image which is created is blocked from access by apparmor .Workaround here https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/696318/comments/9
2. Deletes everything, including the actual image.

$ls /var/lib/libvirt/images/test*
test_webserver_copy.bimg-20151203-093924

$sudo ./fi-backup.sh -C -v -d testserver

[INF] libVirt version '1.2.16' support is experimental [DEB] /usr/bin/qemu-img version '2.3.0' is supported [DEB] QEMU/KVM version '2.3.0' is supported [DEB] Domains NOTRUNNING: [DEB] Domains RUNNING: testserver [DEB] Snapshot for domain 'testserver' requested [DEB] Using timestamp '20151203-104950' [DEB] Snapshotting block devices for 'testserver' using suffix 'bimg-20151203-104950' [VER] Snapshot for block devices of 'testserver' successful [DEB] No backup directory specified [DEB] Consolidation of block devices for 'testserver' requested [DEB] Block devices to be consolidated: /var/lib/libvirt/images/test_webserver_copy.bimg-20151203-104950 [DEB] Consolidation method: blockcommit
[DEB] Consolidation of block device: '/var/lib/libvirt/images/test_webserver_copy.bimg-20151203-104950' for 'testserver'
[DEB] Parent block device: '/var/lib/libvirt/images/test_webserver_copy.bimg-20151203-093924'
[DEB] ABOUT TO RUN:
/usr/bin/virsh blockcommit testserver /var/lib/libvirt/images/test_webserver_copy.bimg-20151203-104950 --wait --pivot --active
[VER] Consolidation of block device '/var/lib/libvirt/images/test_webserver_copy.bimg-20151203-104950' for 'testserver' successful
[VER] Deleting old backup files for 'testserver' [DEB] Processing old backing file '/var/lib/libvirt/images/test_webserver_copy.bimg-20151203-104950' for 'testserver' [DEB] Parent backing file: '/var/lib/libvirt/images/test_webservercopy.bimg-20151203-093924' **[VER] Deleting backing file '/var/lib/libvirt/images/test_webservercopy.bimg-20151203-104950'** [DEB] Next file in backing file chain: '/var/lib/libvirt/images/test_webserver_copy.bimg-20151203-093924' [DEB] Processing old backing file '/var/lib/libvirt/images/test_webserver_copy.bimg-20151203-093924' for 'testserver' [DEB] Parent backing file: '' [VER] Deleting backing file '/var/lib/libvirt/images/test_webserver_copy.bimg-20151203-093924' [DEB] Next file in backing file chain: ''

$ls /var/lib/libvirt/images/test*
ls: cannot access test*: No such file or directory

[dguerri]

Good catch @AJRepo. About base image deletion, the problem here is that the base image name contained the pattern used to create snapshots. Starting from a different filename, don't trigger that bug. But, yes, that's must be fixed! I think that, bedside the image name, we should also check whether the image has a backing file or not. If not, we can assume it's a base image.

About app armour.. well ¯(ツ)/¯ :D

[AJRepo]

Apparmor: I think part of the problem was that in Ubuntu there's no profile for qemu-system-x86_64 which was being called from libvirtd. So I messed around with

$sudo /usr/sbin/aa-genprof qemu-system-x86_64
$sudo /usr/sbin/aa-complain /usr/bin/qemu-system-x86_64

and overriding libvirtd profile rules in /etc/apparmor.d/local/usr.sbin.libvirtd
but there are a number of qemu-system-* program files so I ultimately just disabled libvirt apparmor profile via creating a soft link in /etc/apparmor.d/disable

$sudo ln -s /etc/apparmor.d/usr.sbin.libvirtd /etc/apparmor.d/disable/usr.sbin.libvirtd

---

I've started looking at the script to see about iterating through snapshots without pattern recognition.

[AJRepo]

In looking into this, what's reported is that blockcommit isn't necessarily faster than blockpull, but which to use depends on how large the original vs snapshot images are. So I

• created a flag "-m" which allows one to specify the consolidation type.
• created a function to index all files in the chain so instead of using file name regexp to figure out which file(s) to delete - it just uses the array elements and knowing if it is a blockpull or blockcommit.
• took this branch and used rebase to stick it on the end of the master branch

Commit: https://github.com/AJRepo/LibVirtKvm-scripts/commit/1f230839d40cf0f76f1a3d35bb8c3fa24026def7

Did some basic testing and it seems to work.

[dguerri]

@AJRepo I have pushed your master to mine. Thanks!!!