On 06/01/17 17:12, koukou73gr wrote: > Hello list, > > Today I had to create a new image for a VM. This was the first time, > since our cluster was updated from Hammer to Jewel. So far I was just > copying an existing golden image and resized it as appropriate. But this > time I used rbd create. > > So I "rbd create"d a 2T image and attached it to an existing VM guest > with librbd using: > <disk type='network' device='disk'> > <driver name='qemu'/> > <auth username='lalala'> > <secret type='ceph' uuid='uiduiduid'/> > </auth> > <source protocol='rbd' name='libvirt-pool/srv-10-206-123-87.mails'/> > <target dev='sdc' bus='scsi'/> > <address type='drive' controller='0' bus='0' target='1' unit='0'/> > </disk> > > > Booted the guest and tried to partition it the new drive from inside the > guest. That's it, parted (and anything else for that matter) that tried > to access the new disk would freeze. After 2 minutes the kernel would > start complaining: > > [ 360.212391] INFO: task parted:1836 blocked for more than 120 seconds. > [ 360.216001] Not tainted 4.4.0-78-generic #99-Ubuntu > [ 360.218663] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > disables this message. Is it easy for you to reproduce it? I had the same problem, and the same solution. But it isn't easy to reproduce... Jason Dillaman asked me for a gcore dump of a hung process but I wasn't able to get one. Can you do that, and when you reply, CC Jason Dillaman <jdillama@xxxxxxxxxx> ? > After much headbanging, trial and error, I finaly thought of checking > the enabled rbd features of an existing image versus the new one. > > pre-existing: layering, stripping > new: layering, exclusive-lock, object-map, fast-diff, deep-flatten > > Disabling exclusive-lock (and fast-diff and object-map before that) > would allow the new image to become usable in the guest at last. > > This is with: > > ceph version 10.2.5 (c461ee19ecbc0c5c330aca20f7392c9a00730367) > qemu-img version 2.6.0 (qemu-kvm-ev-2.6.0-28.el7_3.3.1), Copyright (c) > 2004-2008 Fabrice Bellard > > on a host running: > CentOS Linux release 7.3.1611 (Core) > Linux host-10-206-123-184.physics.auth.gr 3.10.0-327.36.2.el7.x86_64 #1 > SMP Mon Oct 10 23:08:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux > > and a guest > DISTRIB_ID=Ubuntu > DISTRIB_RELEASE=16.04 > DISTRIB_CODENAME=xenial > DISTRIB_DESCRIPTION="Ubuntu 16.04.2 LTS" > Linux srv-10-206-123-87.physics.auth.gr 4.4.0-78-generic #99-Ubuntu SMP > Thu Apr 27 15:29:09 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux > > I vagually remember references of problems when exclusive-lock was > enabled on rbd images but trying Google didn't reveal much to me. > > So what is it with exclusive lock? Why does it fail like this? Could you > please point me to some documentation on this behaviour? > > Thanks for any feedback. > > -K. > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- -------------------------------------------- Peter Maloney Brockmann Consult Max-Planck-Str. 2 21502 Geesthacht Germany Tel: +49 4152 889 300 Fax: +49 4152 889 333 E-mail: peter.maloney@xxxxxxxxxxxxxxxxxxxx Internet: http://www.brockmann-consult.de -------------------------------------------- _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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