Re: [libvirt-users] How is calculate the lock with lockd_manager

On Thu, Mar 31, 2016 at 12:05:07PM +0200, villeneu(a)kassis.univ-brest.fr wrote: > Hello > > I use lock_manager with libvirt 1.3 and > I would like to know how is exactly calculate the hash SHA256. I would > create a table > to retreive the name with the hash in case of crash to release manualy > the > lock. Do you mean in the case of a host crash, and if so what filesystem ?  If you are using NFS at lesat so you shouldn't need to know the file names, there is the ability to tell the NFS server to release all locks associated with a dead host. I am using NFS. I have many POOL on an NFS server and I use a special share NFS with all my hypervisors where I put my locks qemu-lock.conf ... lock file_lockspace_dir = "/var/lib/libvirt/images/POOL_ADMIN/lock" ... my POOL are lock file_lockspace_dir = "/var/lib/libvirt/images/POOL_ADMIN/lock" .... my POOL are /var/lib/libvirt/i/var/lib/libvirt/images/POOL_PROD1 /var/lib/libvirt/i/var/lib/libvirt/images/POOL_PROD2 .... In a first time, I tried sanlock with the same configuration but some old VMs often have crashed  and the qemu process were in an anormal state ( defunc ), and I wasn't be able to kill correctly the process. The virsh destroy command couldn't remove the VM. from the virsh list ... and I always got Failed to terminate process xxx with SIGTERM: Device or resource busy and the VM is still in the list I wasn't be able to freeing the resource with sanlock and the result was that I couldn't start a VM which crashed before because the lock was still present. I tried sanlock command to release the resource without success. ie sanlock client rem_lockspace -r

9383 So I decided to try lock_manager , but there is no tools as sanlock to coupled vm name and lock. In a case of crash and if the lock isn't removed I  will be with the same problem, it 's one of the reason I want to create a datatable with sha256 checksum and the vm name. > I do an  sha256 hash from /var/lib/libvirt/images/lock/MyVM.img but I > don't get the same hash code form virtlockd ? It uses the sha256 has of the filename. How did you generate your hash ? If using shell make sure you don't include a newline ie you want   echo -n /var/lib/libvirt/images/lock/MyVM.img | sha256sum not a plain 'echo' as that includes a newline to test before a script with the python libvirt API I am using a very simple python script import hashlib hash_object = hashlib.sha256(b'/var/lib/libvirt/images/POOL_PROD4/WPAD.img') hex_dig = hash_object.hexdigest() print(hex_dig) >>> f52b8ebb9e2922831cf4ff7520ad51ab48af004dbb732155df5e02809a01654c and the lock in the directory when I start the VM is virsh start WPAD ls -alcrt -rw-------  1 root root    0 31 mars  15:02 f12269eb8c7afd6551f2549d245e52182714ae43fd0212626593195a24349605 so I am little confused ... Regards, Daniel Michel -- |: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org              -o-             http://virt-manager.org :| |: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :||: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|