ADSM-L

Re: Lost VCR data

1998-10-25 21:51:14
Subject: Re: Lost VCR data
From: Jennifer Davis <jedavis AT DFW DOT NET>
Date: Sun, 25 Oct 1998 20:51:14 -0600
Matthew,

This is caused by a microcode bug. ADSM does repair the VCR record but when
the
device is improperly closed (the microcode problem), ADSM has to "fix" it
again.

The 3570 device is notorious for this problem. Essentially, the VCR record
is located at the beginning of the tape, before the label, and essentially
keeps track of the end of file / data marker(s).

You can repair the problem external to ADSM by using the 'tapeutil' utility
that is provided with the device driver (Atape.driver) - located in
usr/lpp/Atape.

The command is:
tapeutil -f /dev/rmtX seod (space to end of data)

which essentially will "space" / fast forward across the tape until the end
of data is read and it rewrites / "repairs" the VCR record.
However, since this can take hours (depending on the amount of data on the
tape, it is just smarter to get the microcode update.

You can call IBMs HW support at 1-800-IBM-SERV and request the latest
microcode for your device. It is free of charge (in most cases)- and
usually you can request a tape with the update from the CE. By receiving it
on a tape, you simply load the tape to the drive and the microcode is
automatically updated.

*NOTE: THE CHANGE DOES NOT TAKE EFFECT UNTIL YOU REMOVE AND READD THE
DEVICE DEFINITION AT THE AIX LEVEL. To prepare, take note of your current
configuration with:
lsdev -Cc tape
Then:
Perform the microcode update
Then:
rmdev -dk rmtX
Then:
cfgmgr OR smitty devices (follow the Add a Tape Panels)

Run the 'lsdev' command again and compare it to the out put from before the
update. Make sure that each rmt# has the same scsi id as before to avoid
conflicts within ADSM due to name/addres mismatches.

Best Regards,

Jennifer

At 11:42 AM 10/23/98 +0100, you wrote:
>Hello people,
>
>
>I am having trouble with tapes that have 'Lost VCR Data'
>
>Whenever one of these tapes are mounted ADSM goes through and apparently
repairs the lost VCR data. Thing is, it doesnt work. Next time the tape is
mounted the same thing happens. This is causing big delays with restores.
>
>I know I can move the data off the tape and all will be Ok, but why is
ADSM's repairing of the data not working?
>
>Is it a bad tape? If so then we have quite a few bad tapes in each batch
of new ones we get. The drives are Ok - There are no read / write errors
but despite that I have been cleaning them far more often than they should
need it.
>
>ADSM 2.1.5.18, RS6000. 3570 Tapes libraries + tapes.
>
>Thanks,
>
>Matthew Warren.
>
>
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