[Info-vax] Problems detected with analyze/disk

[JF Mezei]

anwa wrote:
> We are currently double checking the SAN configuration.
> The files marked with MULTALLOC contained corrupted data.
> There was an average of 5-20 corruptions on each disk.

How often did you do ana/disk  ? Is it possible that those accumulated
over the years undetected, or would they have happened all recently ?

Is it possible that they happened a long time ago and whatever
software/conditions caused that is no longer on your system ?


> Out of 15 disks on two clusters half had corruptions. Most are now
> fixed but the ones with "unprintable" filenames remain.

When you boot, do you have a /NOREBUILD paramater to the MOUNT command
in your boot up sequence ? Some site have this to allow system to return
to service faster, but if you don't do a SET VOLUME/REBUILD later on you
 are liable to get some funky stuff. (no sure if this would result in
multiply allocated blocks though).

You should really track down any trend/common denominator for the
affected files. Creation dates, file onwers, and look inside contents to
spot if you see one application's data come out often. In other do some
forensics to find out what application was involved.

Doing a backup may eliminate existing events, but it may not prevent the
problem from reoccuring.

Did ANA/DISK uncover any other problems with the disk ?

Is it possible someone corrupted the bitmap.sys file, telling the system
that some blocks were free when they were not  ? (for instance, restore
the file from an older backup).