Many thanks to all the helpful folks on the list, including 
Alan Rollow
Dr Thomas Blinn
Hines, Bruce D
Brusche, Johan
Chris Bryant
No doubt others of you replied, but I haven't seen the messages
because the host is also our mail server, and I've had it down moving
the filesets to other disks today.
The question was:
   I'm having problems on a fileserver, Digital Unix 4.0E on an Alphaserver
   2100.  Started Sunday in the early morning hours, happened again twice
   Monday night/Tuesday morning.  Many errors similar to the
   following:
     vmunix: AdvFS I/O error:
     vmunix:     Volume: /dev/rz16c
     vmunix:     Tag: 0xfffffffa.0000
     vmunix:     Page: 8404
     vmunix:     Block: 147088
     vmunix:     Block count: 16
     vmunix:     Type of operation: Read
     vmunix:     Error: 5
   The volume, page and block vary but repeat; all are error 5 and nearly all
   the operations are read.  The three volumes are members of the same domain
   (but all domains effectively become inaccessible).
   Is this likely a disk hardware problem?  Perhaps the domain needs to be
   rebuilt?  Any advice welcome.
Use of the commands
   /sbin/advfs/verify
   uerf -R -r 199 -o full -f /var/adm/binary.errlog > errs.txt
was most helpful.  verify showed errors on 2 of about 20 filesets in
the domain; it would not successfully repair them.  The uerf command
showed a large number of soft errors on one volume in the domain, and
a handful of hard errors.  The disk is definitely failing.  Things
were still stable enough to copy the filesets to new domains on newer
drives with vdump/vrestore.  About 3 SCSI errors were reported during
the copy  of ~53 GB.
        ==BD
Received on Tue Apr 08 2003 - 23:05:22 NZST