Hi,
I am preparing to add disks to a raid(swxcr) array. This means
I have to back up the 8GB array. I only have a tlz06(2/4GB) DAT
drive. Using dump this gets about 3.3GB on a tape and takes around
6 hours for the full dump using 3 tapes for the /usr partition.
I use;
dump -0 -b 32 /usr
"man dump" says that "For the dump command, the tape size will be
automatically provided by Digital base system supported devices."
and
"the density will be automatically provided by Digital base system
supported devices."
so I don't add the -d and -s switches.(otherwise they would be
-b 61000 -s 2640)
So far things have been fine. Now however(just when I need to
depend on the dump) the dumps are failing.
On the second volume of the three volume dump the dump failed with
a media error. The system could not eject the tape, and the device
(/dev/rmt0h) was blocked. "mt status" gave a CAM error.
This was only the second time the particular tape had been used.
A reboot partially fixed the problem, I was able to eject the tape,
and do an "mt status" without misshap. I interupted another "mt status"
(cntrl-c) and then the device blocked again. Further exmination just gave
CAM errors.
I swapped the tape drive out for an almost unused tlz07 that was in an
alphastation upstairs, recompiled the kernel etc, booted to single user
mode and tried again(I didn't remake the device files(eg MAKEDEV tz) should I
have?); the tape was new. Failure again.
Then I started to look at the logs(I'm a bit slow some times)
uerf said;
EVENT CLASS ERROR EVENT
OS EVENT TYPE 199. CAM SCSI
SEQUENCE NUMBER 3.
OPERATING SYSTEM DEC OSF/1
OCCURRED/LOGGED ON Thu Feb 6 17:22:50 1997
OCCURRED ON SYSTEM redgum
SYSTEM ID x00020009 CPU TYPE: DEC 2100
SYSTYPE x00000000
----- UNIT INFORMATION -----
CLASS x0001 TAPE
SUBSYSTEM x0000 DISK
BUS # x0000
x0028 LUN x0
TARGET x5
and every time the system is rebooted the following appears in the
/var/adm/messages file, and on the screen.
vmunix: cam_logger: CAM_ERROR packet
vmunix: cam_logger: bus 0 target 5 lun 0
vmunix: ss_device_reset_done
vmunix: Bus device reset has been performed
The following is typical of the CAM errors I get.
vmunix: cam_logger: CAM_ERROR packet
vmunix: cam_logger: bus 0 target 5 lun 0
vmunix: ctape_iodone
vmunix: Hard Error Detected
vmunix: DEC TLZ06
vmunix: Active CCB at time of error
vmunix: CCB request completed with an error
vmunix: Error, exception, or abnormal condition
vmunix: MEDIUM ERROR - Nonrecoverable medium error
If its a medium error then why the Bus device reset on boot,
and how come its happening with new tapes?
What do you think, have I just got a bad batch of tapes?
(new ones are on order) if so it doesn't say much for
DAT tape reliability.
I'd REALLY appreciate your thoughts on this.
TIA
boc
--
------------------------------------------------------------
Brian O'Connor, Unix Systems Consultant
Latrobe University,Bendigo
boc_at_ironbark.bendigo.latrobe.edu.au
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Received on Sat Feb 08 1997 - 07:49:12 NZDT