I'm not reporting this formally to IBM since we can't recreate it,
but thought some of you might be interested.

On one of our AIX machines, the ADSM client (R1) reported

 ANS4253E File input/output error

on each scheduled backup of the filesystem "/".  Knowing that the
latest and greatest AIX client (IP20177) fixed a problem where a
problem occured but the problem file was not displayed, we installed
the new client software.

The (R2L0.3--IP20177) client reported the same message!  When the
backup client was manually invoked, a more descriptive message was
issued (approximately: error reading directory /cdrom).

Using the MOUNT command, we found /cdrom was NFS mounted.  Using LS
we received a message that said there was no directory /cdrom.  I
don't know how we got into that state, but ADSM, and one might say
AIX were a bit confused ... and not very helpful.

Perhaps most importantly, filesystem "/" was not backed up during
the time it took to resolve this problem.  I would have hoped that
ADSM would have continued past this problem (it did do other
filsystems), but would have expected a return code greater than the
one we received (4) for the case of failure on a filesystem level.

cheers,

Wayne T. Smith
Systems Group -- CAPS        internet: wts AT maine.maine DOT edu
University of Maine System   BITNET/CREN: WTS@MAINE