Re: [BUG] kernel panics with drbd

[Ian Campbell <ian.campbell@citrix.com>]

On Tue, 2015-08-04 at 22:24 +0100, Matthew Vernon wrote:
> On 04/08/15 15:39, Matthew Vernon wrote:
> > Hi,
> > 
> > On 04/08/15 15:22, Ian Campbell wrote:
> > > On Tue, 2015-08-04 at 14:52 +0100, Matthew Vernon wrote:
> > > > Hi,
> > > 
> > > Hello,
> > > 
> > > > I'm getting dom0 kernel panics, relating to moderately heavy use of
> > > > drbd. I think this is a Xen bug.
> > > 
> > > It is remarkably similar looking to
> > > http://blog.chinewalking.com/drbd-kernel-oops-w-trim/ . Do you have 
> > > trim?
> > 
> > I seem to, yes:
> > 
> > Aug  4 14:28:24 ophon kernel: [2856757.049680] drbd mws-02474: Agreed 
> > to
> > support TRIM on protocol level
> > 
> > I have DRBD 8.9.2~rc1-2.
> 
> [FTAOD, I think this means that this cannot be a repeat of the issue 
> mentioned in that blog post?]

I must confess I'm a bit confused about the versioning of drbd, while
Jessie ships the 8.9.2~rc1-2 userspace it appears (from inspection of the
kernel source) to contain version 8.4.3 of the kernel side.

I think it's the kernel side which the blog post is referring too, which
would also be consistent with the kernel side crash.

What does /proc/drbd say for you?

My usual first suggestion would be to try a newer kernel from jessie
-backports, but there doesn't appear to be one right now. Depending on the
nature of the systems (e.g. production vs. testlab) you could consider
installing the 4.0.8 kernel from Stretch.

Alternatively I don't know if drbd upstream provides a convenient way to
build and install the modules in an out of tree way?

Or maybe there is some option somewhere to tell drbd to not attempt to do
trim, even if it thinks it can?

Ian.