Re: provisioning clients in teuthology with an extra local filesystem

[Jeff Layton <jlayton@redhat.com>]

On Tue, 2020-12-01 at 16:31 -0500, David Galloway wrote:
> On 12/1/20 3:07 PM, Jeff Layton wrote:
> > On Tue, 2020-12-01 at 14:23 -0500, David Galloway wrote:
> > > 
> > > On 12/1/20 10:24 AM, Jeff Layton wrote:
> > > > On Tue, 2020-12-01 at 10:22 -0500, David Galloway wrote:
> > > > > On 12/1/20 9:55 AM, Jeff Layton wrote:
> > > > > > I've been working on a patch series to overhaul the fscache code in the
> > > > > > kclient. I also have this (really old) tracker to add fscache testing to
> > > > > > teuthology:
> > > > > > 
> > > > > >     https://tracker.ceph.com/issues/6373
> > > > > > 
> > > > > > It would be ideal if the clients in such testing had a dedicated
> > > > > > filesystem mounted on /var/cache/fscache, so that if it fills up it
> > > > > > doesn't take down the rootfs with it. We'll also need to have
> > > > > > cachefilesd installed and running in the client hosts.
> > > > > > 
> > > > > > Is it possible to do this in teuthology? How would I approach this?
> > > > > > 
> > > > > 
> > > > > I think I can make this happen pretty easily in ceph-cm-ansible.  What
> > > > > I'd need from you is desired filesystem type and size.  Once I'm done
> > > > > with my end, we'll need to create a cephlab.ansible overrides yaml
> > > > > fragment to stick in that suite's qa directory.
> > > > > 
> > > > 
> > > > Ok, cool:
> > > > 
> > > > fstype: xfs or ext4 (either is fine)
> > > > size: ~50g or so would be ideal, but we can probably get away with less 
> > > >       if necessary
> > > > 
> > > 
> > > Getting there...
> > > 
> > > https://github.com/ceph/ceph-cm-ansible/pull/592
> > > 
> > > Can you give me an optimal cachefilesd.conf and I'll set that up in
> > > ceph-cm-ansible too?
> > > 
> > 
> > I never actually tweak the defaults in my local testing, so let's start
> > with a default cachefilesd.conf as installed by the package. If we need
> > to tweak it later, then we'll go from there.
> > 
> 
> K.  I made it optional and used the package-provided defaults.
> 
> Your requested changes are implemented in ceph-cm-ansible.  I've
> attached the yaml fragments you'll need to pass on the
> `teuthology-suite` command line to set up the partition, filesystem, and
> cachefilesd service.
> 
> e.g., teuthology-suite ... ~/fs-cache-smithi.yml

Many thanks! I now need to figure out how to pass arbitrary mount
options to the kclient. I think that might need some plumbing down in
ceph/qa. I'll sort that out soon and test this.

Cheers!
-- 
Jeff Layton <jlayton@redhat.com>