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Bug 861439 - RFE: More info in qemu-img info
Summary: RFE: More info in qemu-img info
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: qemu-kvm
Version: 7.0
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: ---
Assignee: Stefan Hajnoczi
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On: 861375
Blocks:
TreeView+ depends on / blocked
 
Reported: 2012-09-28 15:35 UTC by Paolo Bonzini
Modified: 2014-06-18 03:18 UTC (History)
16 users (show)

Fixed In Version: QEMU 1.5
Doc Type: Enhancement
Doc Text:
Clone Of: 861375
Environment:
Last Closed: 2014-06-13 11:09:01 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)

Description Paolo Bonzini 2012-09-28 15:35:58 UTC 
+++ This bug was initially created as a clone of Bug #861375 +++

qemu-img info currently give me info like this:

image: /home/alex/.local/share/gnome-boxes/images/Fedora 16
file format: qcow2
virtual size: 11G (11794287616 bytes)
disk size: 4.5G
cluster_size: 65536

In order to figure out the "health" of an image there is some more information I would like:

in-use disk size - I.e the subset of disk size that is not marked as unused due to e.g. TRIM operations

amount of compressed clusters. I.e. "is it useful to re-compress the image".

Fragmentation estimation.

This would be useful to both sysadmins in general and for automated things like
what we want to do in gnome-boxes:
https://bugzilla.gnome.org/show_bug.cgi?id=685032

--- Additional comment from rjones on 2012-09-28 08:18:50 EDT ---

All sounds useful.  However these requests should probably
go upstream, along with patches!

Note upstream there is a patch floating around which adds
JSON output to qemu-img info.  This is useful because it's
a big security problem to try to parse the text output from
this command.  See:

https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg00137.html
Comment 1 Stefan Hajnoczi 2013-03-11 15:05:50 UTC 
Fragmentation, allocation, and compressed cluster statistics are available in "qemu-img check" upstream.

$ qemu-img info test.qcow2
image: test.qcow2
file format: qcow2
virtual size: 16G (17179869184 bytes)
disk size: 1.8G
cluster_size: 65536
$ qemu-img check test.qcow2
No errors were found on the image.
29877/29902 = 99.92% allocated, 0.00% fragmented, 0.00% compressed clusters
Image end offset: 1959657472

Both "qemu-img check" and "qemu-img info" support --output json for programmatic queries.

Marking as complete, please try qemu.git/master qemu-img and raise new bugs if you need other enhancements.
Comment 3 Xu Han 2014-01-23 07:22:44 UTC 
Test result of qemu-img-1.3.0-6.el7.x86_64

# qemu-img info RHEL-Server-7.0-64-virtio.qcow2
image: RHEL-Server-7.0-64-virtio.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 13G
cluster_size: 65536

# qemu-img check RHEL-Server-7.0-64-virtio.qcow2
No errors were found on the image.
----
Test result of qemu-img-1.5.3-40.el7.x86_64

# qemu-img info RHEL-Server-7.0-64-virtio.qcow2
image: RHEL-Server-7.0-64-virtio.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 13G
cluster_size: 65536
Format specific information:
    compat: 0.10

# qemu-img check RHEL-Server-7.0-64-virtio.qcow2 
No errors were found on the image.
214519/327680 = 65.47% allocated, 0.48% fragmented, 0.00% compressed clusters
Image end offset: 14061338624

----
Base on these test results above, this bug has been fixed.
Comment 5 Ludek Smid 2014-06-13 11:09:01 UTC 
This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.
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