Frank Batschulat (Home) wrote:
> On Tue, 02 Dec 2008 10:24:59 +0100, Pavel Filipensky <Pavel.Filipensky at
> sun.com> wrote:
>
>
>> usefully attempt an all-zones umountall'. Fix for "6675447 NFSv4 client
>> hangs on shutdown if server is down beforehand"- has added the '-l' flag
>> (limit actions to the local file systems) to svc.startd:
>> system("/sbin/umountall -l" with this fix, we no longer unmount NFS there.
>>
>
> a bit of topic in the context of this proposal, but still...
> fwiw, I have to disagree here, despite the assumption above, I can
> prove you that 'umountall -l' still does attempt to unmount NFS file systems.
>
Interesting. The root cause is in /usr/sbin/umountall and how it
processes /etc/mnttab.
E.g. we have mounted NFS file system on mountpoint
/net/tb3.uk/tank/src/onnv-snapshots/onnv_66
via autofs:
/etc/mnttab will contain these 2 lines:
tb3.uk:/tank/src/onnv-snapshots/onnv_66
/net/tb3.uk/tank/src/onnv-snapshots/onnv_66 nfs
-hosts /net/tb3.uk/tank/src/onnv-snapshots/onnv_66 autofs
/sbin/umountall -l will do this check:
if [ -n "$LFLAG" -a "$fstype" = "nfs" ]; then
continue
fi
obviously it will skip nfs, but will proceed with autofs - since both
use the same mountpoint,
the call 'umount -a /net/tb3.uk/tank/src/onnv-snapshots/onnv_66' does
not know that it should
do the 'autofs' unmount (which should return EBUSY) and will do the 'nfs
'unmount and will hang.
The fix "6675447 NFSv4 client hangs on shutdown if server is down
beforehand"
is not working for autofs/nfs mounts - must be reopened.
--Pavel
