https://tracker.ceph.com/https://tracker.ceph.com/favicon.ico2013-02-22T11:53:10ZCeph rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=177522013-02-22T11:53:10ZJosh Durgin
<ul></ul><p>This is something that we should fix. Is it still an issue in current libvirt?</p> rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=177912013-02-22T13:23:56ZAndrey Korolyovandrey@xdel.ru
<ul></ul><p>Just checked, problem with blkdeviotune still exists in the 1.0.2.</p> rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=187352013-03-13T11:53:47ZWido den Hollanderwido@42on.com
<ul><li><strong>Assignee</strong> set to <i>Wido den Hollander</i></li></ul><p>Sage just pinged me about this bug report.</p>
<p>I'll pick this up and write patch for libvirt to fix this.</p> rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=200442013-04-05T08:39:30ZWido den Hollanderwido@42on.com
<ul><li><strong>File</strong> <a href="/attachments/download/757/0001-qemu-Do-not-require-devices-to-be-blocks-or-files-wh.patch">0001-qemu-Do-not-require-devices-to-be-blocks-or-files-wh.patch</a> <a class="icon-only icon-magnifier" title="View" href="/attachments/757/0001-qemu-Do-not-require-devices-to-be-blocks-or-files-wh.patch">View</a> added</li></ul><p>I've just submitted a patch for this to libvirt (also attached).</p>
<p>I tested it locally with libvirt 1.0.4 and it works just fine on my test system.</p>
<p>One thing I noted, which doesn't seem related to RBD is that a Virtual Machine becomes very slow and unresponsive when you hit the I/O limit, much slower then with a 100% utilized disk.</p> rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=200452013-04-05T08:39:44ZWido den Hollanderwido@42on.com
<ul><li><strong>% Done</strong> changed from <i>0</i> to <i>60</i></li></ul> rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=200462013-04-05T08:56:36ZAndrey Korolyovandrey@xdel.ru
<ul></ul><blockquote>
<p>One thing I noted, which doesn't seem related to RBD is that a Virtual Machine becomes very slow and unresponsive when you hit the I/O limit, much slower then with a 100% utilized disk.</p>
</blockquote>
<p>You meant in comparison with physical machine? Qemu is a way slower due to single-threaded self-nature, and seems that it is unsolvable in near future or so.</p> rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=200482013-04-05T09:13:33ZWido den Hollanderwido@42on.com
<ul></ul><p>Andrey Korolyov wrote:</p>
<blockquote><blockquote>
<p>One thing I noted, which doesn't seem related to RBD is that a Virtual Machine becomes very slow and unresponsive when you hit the I/O limit, much slower then with a 100% utilized disk.</p>
</blockquote>
<p>You meant in comparison with physical machine? Qemu is a way slower due to single-threaded self-nature, and seems that it is unsolvable in near future or so.</p>
</blockquote>
<p>Yes, compared to a physical machine. The VM becomes so slow it's not useable anymore. The throttling works nice though, it's not going over the limits.</p>
<p>With a physical machine stuff still works, but very slow. A VM completely stalls.</p> rbd - Bug #2700: blkdeviotune method at libvirt doesn`t work on RBD volumeshttps://tracker.ceph.com/issues/2700?journal_id=208922013-04-25T01:02:59ZWido den Hollanderwido@42on.com
<ul><li><strong>Status</strong> changed from <i>New</i> to <i>Resolved</i></li><li><strong>% Done</strong> changed from <i>60</i> to <i>100</i></li></ul><p>The patch got accepted into libvirt: <a class="external" href="http://www.libvirt.org/git/?p=libvirt.git;a=commit;h=e3e866aee0f8b0b125da74e1afcfe7242c2fe3d2">http://www.libvirt.org/git/?p=libvirt.git;a=commit;h=e3e866aee0f8b0b125da74e1afcfe7242c2fe3d2</a></p>
<p>Closing this one as it is resolved.</p>