[Pkg-iscsi-maintainers] Bug#498616: Unmounting LVM'd isci based filesystem

[Ritesh Raj Sarraf]

On Tuesday 08 Jun 2010 19:54:12 Ritesh Raj Sarraf wrote:
> > We (as debian user) have another problem with lenny and iscsi + lvm +
> >
> > multipath (should I open another bug?). I try to explain it here:
> > 
> >
> > # pwd
> > /etc/rc6.d
> > # ls -1 multipath iscsi lvm
> > K20multipath-tools
> > K80umountiscsi.sh
> > K81open-iscsi
> > S50lvm
> > S50lvm2
> >
> > 
> >
> > Suppose I have a pv in iscsi lun, and over it a vg, who has a lv.
> > So if multipath is down, how umountiscsi is capable to unmount lvm
> > volume?
> >
> > 
> >
> > My server hangs forever when is rebooting or shutting down. With sys+rq W
> > debian said to me there is a process lvchange who is blocked. I can read
> > in redhat issue tracker [1] about similar bug in redhat systems.
> >
> > 
> >
> > Is it possible to "full" support lvm inside iscsi luns ?


For this problem of yours', I had proposed the kernel team for the "Panic on 
Hung Task" feature. But it was not included.
You might want to advocate for that bug and ask the kernel team to enable the 
feature. Debian BTS #550358

Otherwise, with multipath's "queue_if_no_path" enabled and you lose all paths 
to your LUN, you are out of luck.

The idea is the above bug is:
* Kernel detect Hung Task.
* Kernel Panics on Hung Task
* Kernel reboot/reset on Panic

Not the best, but better than going into the data center and hard resetting 
the machine.


-- 
Ritesh Raj Sarraf | http://people.debian.org/~rrs
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 836 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.alioth.debian.org/pipermail/pkg-iscsi-maintainers/attachments/20100609/988cf1af/attachment.pgp>