am-utils/NFS mount lockups in 8.0
Bob Friesenhahn
bfriesen at simple.dallas.tx.us
Sat Dec 19 19:09:05 UTC 2009
After upgrading my FreeBSD system from FreeBSD 7.2 to 8.0, the
am-utils automounter is experiencing difficulty with managing the NFS
client mounts to my Solaris 10U8 system. There have never been any
difficulties before. This is when using the NFSv3/TCP in the default
kernel and not the new NFSv4 implementation. If it matters, this is
for NFS exports from a ZFS pool, with an exported filesystem per user.
The problem I see is that the initial mount is instantaneous and works
great. After the mount times out, the re-mount produces several "NFS
timeout" messages to the widow where the accessing program is running.
Sometimes this remount succeeds, but if it fails, then the program is
left locked up forever waiting for the NFS mount. Meanwhile
connectivity between the FreeBSD system and the Solaris system is
fine, as illustrated by excellent connectivity with SSH and no lost
packets via 'ping'.
The amd log file (/var/log/amd.log) shows no sign of any difficulties.
The only complaint is due to an occasional attempt to mount /home/svn
even though there is no 'svn' user in /etc/passwd. Perhaps this is
due to some action of portupgrade since during this time all of the
ports are being rebuilt. It is indeed quite curious that the last
entry I see in amd.log (prior to entries caused by me killing the amd
daemon) is an attempt to mount /home/svn:
Dec 18 20:06:36 shaggy amd[651]/map: Trying mount of freddy:/home/svn on /.amd_mnt/freddy/home/svn fstype nfs mount_type non-autofs
Dec 18 20:14:20 shaggy amd[651]/warn: WARNING: automounter going down on signal 15
Notice that this "Trying mount" attempt did not obtain a response from
the OS and perhaps amd is essentially locked up after that point.
>From checking the log file, I see that there are 47 attempts to mount
/home/svn since the upgrade to 8.0 and no such attempts with FreeBSD
7.2.
It is difficult for me to tell if this is some issue with am-utils, or
kernel code. It seems that am-utils was updated for 8.0 and there
have been changes in the area of NFS as well in order to accommodate
the new NFSv4 implementation.
Any ideas?
Bob
--
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
More information about the freebsd-fs
mailing list