Lustre discuss - Mar 2012 - Fwd: can't mount our lustre filesystem after tunefs.lustre --writeconf

---------- Forwarded message ----------
From: Stu Midgley <sdm900 at gmail.com>
Date: Sat, Mar 17, 2012 at 5:10 PM
Subject: can''t mount our lustre filesystem after tunefs.lustre
--writeconf
To: wc-discuss at whamcloud.com


Afternoon

We have a rather severe problem with our lustre file system. ?We had a
full config log and the advice was to rewrite it with a new one. ?So,
we unmounted our lustre file system off all clients, unmount all the
ost''s and then unmounted the mds. ?I then did

mds:
? tunefs.lustre --writeconf --erase-params /dev/md2

oss:
? tunefs.lustre --writeconf --erase-params --mgsnode=mds001 /dev/md2



After the tunefs.lustre on the mds I saw

Mar 17 14:33:02 mds001 kernel: Lustre: MGS MGS started
Mar 17 14:33:02 mds001 kernel: Lustre: MGC172.16.0.251 at tcp: Reactivating
import
Mar 17 14:33:02 mds001 kernel: Lustre: MGS: Logs for fs p1 were
removed by user request. ?All servers must be restarted in order to
regenerate the logs.
Mar 17 14:33:02 mds001 kernel: Lustre: Enabling user_xattr
Mar 17 14:33:02 mds001 kernel: Lustre: p1-MDT0000: new disk, initializing
Mar 17 14:33:02 mds001 kernel: Lustre: p1-MDT0000: Now serving
p1-MDT0000 on /dev/md2 with recovery enabled

which scared me a little...



the mds and the oss''s mount happily BUT I can''t mount the file
system
on my clients... on the mds I see


Mar 17 16:42:11 mds001 kernel: LustreError: 137-5: UUID
''prod_mds_001_UUID'' is not available ?for connect (no target)


On the client I see


Mar 17 16:00:06 host kernel: LustreError: 11-0: an error occurred
while communicating with 172.16.0.251 at tcp. The mds_connect operation
failed with -19


now, it appears the writeconf renamed the UUID of the mds from
prod_mds_001_UUID to p1-MDT0000_UUID but I can''t work out how to get
it back...


for example I tried


# tunefs.lustre --mgs --mdt --fsname=p1 /dev/md2
checking for existing Lustre data: found CONFIGS/mountdata
Reading CONFIGS/mountdata

?Read previous values:
Target: ? ? p1-MDT0000
Index: ? ? ?0
UUID: ? ? ? prod_mds_001_UUID
Lustre FS: ?p1
Mount type: ldiskfs
Flags: ? ? ?0x405
? ? ? ? ? ? (MDT MGS )
Persistent mount opts: errors=remount-ro,iopen_nopriv,user_xattr
Parameters:

tunefs.lustre: cannot change the name of a registered target
tunefs.lustre: exiting with 1 (Operation not permitted)



I''m now stuck not being able to mount a 1PB file system... which
isn''t good :(

--
Dr Stuart Midgley
sdm900 at gmail.com


-- 
Dr Stuart Midgley
sdm900 at gmail.com