On Thu, Mar 01, 2018 at 04:23:32PM +0100, Alwin Antreich wrote: > On Thu, Mar 01, 2018 at 10:59:15AM +0100, Fabian Grünbichler wrote: > > this is problematic because it potentially hides bugs in our application > > logic, with currently no benefit. > > > > with exclusive-locks disabled, mapping on multiple hosts is possible, > > but mounting the same image is not (e.g., when attempting to mount, all > > but the first successful node will fail). > > > > with exclusive-locks enabled, mapping and accessing/mounting is > > sometimes possible (it seems a bit racy?), but since ext4 is not a > > cluster FS, this will cause undesired behaviour / inconsistencies / > > corruption. > > > > OTOH, with exclusive-locks enabled we would have the option of exclusive > > mapping - if we find a way to make this work with Qemu live-migration it > > might solve all of our problems > > > > TL;DR: I think we should postpone this pending further investigations > > into potential pros and cons > > > I did some testing on this topic. Qemu dies when live migrating, as rbd > can not get the lock on the new destination. A offline migration is > possible. > > I guess, if we want to use it, then either we get qemu to work > differntly on migration or only allow offline migration when > exclusive mapping is requested. > > I am up for discussion. > > > _______________________________________________ > pve-devel mailing list > [email protected] > https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel As to do once the kernel rbd client is able to down-/upgrade the exclusive lock.
https://bugzilla.proxmox.com/show_bug.cgi?id=1686 _______________________________________________ pve-devel mailing list [email protected] https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
