On Thu, Jul 17, 2014 at 1:28 AM, Marcin Gibuła <m.gib...@beyond.pl> wrote: >> Tested on iscsi pool, though there are no-cache requirement and rbd >> with disabled cache may survive one migration but iscsi backend hangs >> always. As it was before, just rolling back problematic commit fixes >> the problem and adding cpu_synchronize_all_states to migration.c has >> no difference at a glance in a VM` behavior. The problem consist at >> least two separate ones: the current hang and behavior with the >> unreverted patch from agraf - last one causes live migration with >> writeback cache to fail, cache=none works well in any variant which >> survives first condition. Marcin, would you mind to check the current >> state of the problem on your environments in a spare time? It is >> probably easier to reproduce on iscsi because of way smaller time >> needed to set it up, command line and libvirt config attached >> (v2.1.0-rc2 plus iscsi-1.11.0). > > > Ok, but what exacly do you want me to test? > > Just to avoid any confusion, originally there were two problems with > kvmclock: > > 1. Commit a096b3a6732f846ec57dc28b47ee9435aa0609bf fixes problem when clock > drift (?) caused kvmclock in guest to report time in past which caused guest > kernel to hang. This is hard to reproduce reliably (probably as it requires > long time for drift to accumulate). > > 2. Commit 9b1786829aefb83f37a8f3135e3ea91c56001b56 fixes regression caused > by a096b3a6732f846ec57dc28b47ee9435aa0609bf which occured during > non-migration operations (drive-mirror + pivot), which also caused guest > kernel to hang. This is trival to reproduce. > > I'm using both of them applied on top of 2.0 in production and have no > problems with them. I'm using NFS exclusively with cache=none. > > So, I shall test vm-migration and drive-migration with 2.1.0-rc2 with no > extra patches applied or reverted, on VM that is running fio, am I correct? >
Yes, exactly. ISCSI-based setup can take some minutes to deploy, given prepared image, and I have one hundred percent hit rate for the original issue with it. > -- > mg