Re: [Xen-users] Database crashes when using Xen PVH

[Tomas Mozes <hydrapolic@xxxxxxxxx>]

On Mon, Jul 4, 2016 at 12:53 PM, Roger Pau Monné <roger.pau@xxxxxxxxxx> wrote:

Hello,

Thanks for the report.

On Mon, Jun 20, 2016 at 03:10:02PM +0200, Tomas Mozes wrote:
> We observed several crashes on MariaDB databases when using Xen PVH mode.
> After switching back to Xen PV, all fine. The strange thing is that on
> application servers it works just fine (speeded up compilation times by
> 30%).
>
> Gentoo Linux with kernel 4.1, Xen 4.6.0/4.6.1.
>
> More details reported on Gentoo / MariaDB bug trackers:
> https://bugs.gentoo.org/show_bug.cgi?id=584828
> https://jira.mariadb.org/browse/MDEV-10167

The PVH mode you are using (pvh = 1 in the config file) is being replaced by
a new implementation, and we are still in the transition period, therefor,
it's not recommended for production usage, and it's very unlikely that
anyone is going to work on bugfixing it, most of the effort is concentrated
in getting the new implementation into a production state. I would recommend
that you switch to PVHVM mode, that has the same performance as PVH, and is
fully supported. If you still see the crash (SIGSEV) in PVHVM mode, please
report back.

Thanks, Roger.

Is there a way to migrate from PV to PVHVM? I thought that I need something like a single image file or partition with grub for example (much like HVM).

In my case, all domU filesystems are lvm volumes on dom0 directly, the configuration looks like:

name = "virtual"
kernel = "/path/to/kernel"
extra = "root=/dev/xvda1 net.ifnames=0"
memory = 5000
vcpus = 12
vif = [ '' ]
disk = [ '/dev/vg_data/virtual_root,raw,xvda1,rw',
         '/dev/vg_data/virtual_var,raw,xvda2,rw',
         '/dev/vg_data/virtual_tmp,raw,xvda3,rw',
         '/dev/vg_data/virtual_opt,raw,xvda4,rw',
         '/dev/vg_data/virtual_home,raw,xvda5,rw' ]

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxx
https://lists.xen.org/xen-users