NW 6.5 SP6
NSS pool POOL1 with volumes VOL1 and MAIL

After the NSS background check we receive following error:
NSS background check running (1)...
Doing NSS background check of user IDs on volume SYS
Doing NSS background check of directory quotas on volume SYS
Doing NSS background check of files on volume SYS
Doing NSS background check of user IDs on volume MAIL
Doing NSS background check of directory quotas on volume MAIL
Doing NSS background check of files on volume MAIL
Doing NSS background check of user IDs on volume VOL1
Doing NSS background check of directory quotas on volume VOL1
Doing NSS background check of files on volume VOL1
NSS background check completed (1)...

1 Sep 2007 16:23:42 NSS<COMN>-3.25-xxxx: comnPool.c[2629]
Pool POOL1: System data error 20012(beastTree.c[510]). Block
23579655(file
block -23579655)(ZID 1)


1 Sep 2007 16:23:42 NSS<COMN>-3.25-xxxx: comnVol.c[8852]
Volume VOL1: System data error 20012(beastTree.c[510]). Block
23579655(fil
e block -23579655)(ZID 1)

On second background check same error.

Command 'nss /ErrorCode=20012' gives result:
Error=zERR_MEDIA_CORRUPTED

I can't find a lott on this error on support.novell.com knowledge base.

Last time I had such errors I had to recreate the pool and restore all data.
Not a very funny procedure.

Anyone knows what this error exactly means and what I can do to fix it??

Kind regards,
Mario van Rijt
system administrator