Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!apple!oliveb!pyramid!amdcad!neptune!markl
From: markl@neptune.AMD.COM (Mark Luedtke)
Newsgroups: comp.sys.apollo
Subject: Re:  Deteriorating Media
Summary: disk and ct inaccessable
Keywords: ct, disk
Message-ID: <1082@neptune.AMD.COM>
Date: 6 Sep 89 23:44:43 GMT
Reply-To: markl@neptune.AMD.COM (Mark Luedtke)
Followup-To: comp.sys.apollo
Organization: Advanced Micro Devices, Inc., Austin, Texas
Lines: 34
References:

We have a dsp3550 with two 760Mb drives.  A couple of weeks ago we had the
primary drive replaced as disk data check errors were occuring at an increasing
frequency.  When we went to load the user data back, we found our backups were
not complete, so we had our Mentor representative install the disk in one of
his machines and dump a tape (they use cartridge almost exclusively).  Well,
after getting the tape here, we couldn't read beyond some tape error to get at
the two projects we need restored.  The rep then had problems writing another
tape.  Now the drive is reinstalled here, but it won't mount since the logical
volume header appears to be corrupted.

Question #1:
Does anyone know of a way to get at the data on the tape (probably the better
copy)?  RBAK dies at some location and will not find anything further, but if
I could get it to start looking further down, I should be able to access the
data.  An index, using RBAK, will pass the bad spot, but reading won't and
using '-f cur' tells me that the current location is unknown.  Can I use RWMT
in raw mode to build a file then RBAK from that file?  Any options at all
for the tape?

Question #2:
I'm sure most of the data is still on the disk, but how can I get to it?
Using fixvol I can get make the PV ok, but the LV and ALV are trashed (disk
data check again).  I also tried using UNIX mkdisk with mount and dd, but
dd only read what appeared to be some header information then quit with no
error message; mount claimed the volume was in use.  Any suggestions for
dumping the disk?

We are running 9.7.5 and the machine is mounted diskless off a dn3550.  We
also run BSD4.2, and I could probably install SYS V if it would help.  Any help
is appeciated.

Mark Luedtke    markl@neptune.amd.com    (512)462-5278

Disclaimer (?) My spelling is a work of art