On 10/8/19 12:54 PM, Daniel Berteaud wrote: > ----- Le 8 Oct 19, à 12:28, Thomas Lamprecht t.lampre...@proxmox.com a écrit : > >> >> Thanks for the nice write up and clear reproducer! >> >> It seems that if we cannot use the same backend for all disks we need to >> die when a disk move to a storage backend is request, and that move would >> need to change the scsi "backend". >> As I'd not like to die it would be better to see if there's still the need >> for different backends. > > Dying wouldn't be very nice indeed (I need to be able to move disks between > NFS and ZFS over iSCSI on a regular basis) > > If scsi-hd was always selected, there would be no issue. I've patched my > QemuServer.pm to do that for now. > Not sure if scsi-generic/scsi-block has any advantages, but I couldn't > measure performance diff in my case. unmap is also passed correctly with > scsi-hd. IMHO, unless there are strong values with them (which I'am unaware > off, but I couldn't find any documentation about all those backends), we > should always use scsi-hd, as it's working with all storage types and allows > live disk move from any storage type to any other, including the issue I have > specific to ZFS over iSCSI (guest I/O error during live move from ZFS over > iSCSI to something else)
I would actually really like to change this to scsi-hd, but we need to be sure it's OK for all possible supported setups.. So I tried to investigate a bit how it came to the use of scsi-generic, I came to a commit[0] from Alexandre (CCd) which adds support for access with libiscsi. Maybe he knows why the -generic was used and not the -hd one? [0]: https://git.proxmox.com/?p=qemu-server.git;a=commitdiff;h=d454d040338a6216c8d3e5cc9623d6223476cb5a cheers, Thomas _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
