On Thu, Jan 21, 2016 at 2:54 PM, Pavel Gashev <p...@acronis.com> wrote: > Hello, > > First of all I would like to ask if anybody has an experience with using > Microsoft NFS server as a storage domain. > > The main issue with MS NFS is NTFS :) NTFS doesn't support sparse files. > Technically it's possible by enabling NTFS compression but it has bad > performance on huge files which is our case. Also there is no option in > oVirt web interface to use COW format on NFS storage domains.
You can 1. create a small disk (1G) 2. create a snapshot 3. extend the disk go the final size And you have nfs with cow format. The performance difference with one snapshot should be small. > Since it looks like oVirt doesn't support MS NFS, I decided to migrate all > my VMs out of MS NFS to another storage. And I hit a bug. Live storage > migration silently corrupts data if you migrate a disk from MS NFS storage > domain. So if you shutdown just migrated VM and check filesystem you find > that it has a lot of unrecoverable errors. > > There are the following symptoms: > 1. It corrupts data if you migrate a disk from MS NFS to Linux NFS > 2. It corrupts data if you migrate a disk from MS NFS to iSCSI > 3. There is no corruption if you migrate from Linux NFS to iSCSI and vice > versa. > 4. There is no corruption if you migrate from anywhere to MS NFS. > 5. Data corruption happens after 'Auto-generated for Live Storage Migration' > snapshot. So if you rollback the snapshot, you could see absolutely clean > filesystem. Can you try to create a live-snapshot on MS NFS? It seems that this is the issue, not live storage migration. Do you have qemu-guest-agent on the vm? Without qemu-guest-agent, file systems on the guest will no be freezed during the snapshot, which may cause inconsistent snapshot. Can you reproduce this with virt-manager, or by creating a vm and taking a snapshot using virsh? > 6. It doesn't depend on SPM. So it corrupts data if SPM is on the same host, > or another. > 7. There are no error messages in vdsm/qemu/system logs. > > Yes, of course I could migrate from MS NFS with downtime – it's not an > issue. The issue is that oVirt does silently corrupt data under some > circumstances. > > Could you please help me to understand the reason of data corruption? Please file a bug and attach: - /var/log/vdsm/vdsm.log - /var/log/messages - /var/log/sanlock.log - output of nfsstat during the test, maybe run it every minute? > vdsm-4.17.13-1.el7.noarch > qemu-img-ev-2.3.0-31.el7_2.4.1.x86_64 > libvirt-daemon-1.2.17-13.el7_2.2.x86_64 > ovirt-engine-backend-126.96.36.199-1.el7.centos.noarch > > Thank you > > > > _______________________________________________ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users