[daip] tape probs

[Patrick P. Murphy]

(no need to send to both daip and me; I'm on the daip alias).

On Thu, 18 May 2000 15:23:48 -0600 (MDT), Ka Chun Yu
   <kachun at casa.Colorado.EDU> said: 

> Hi Patrick,
>> >   FITLD1: Create 20000430    .LINE  .   1 (UV)  on disk  4  cno    6
>> >   FITLD1: TAPIO: RECORD LENGTH  24318 INCONSISTENT WITH BLOCK SIZE  2880
>> 
>> This looks to me like a bad record on the tape, or a bad read.  In either
>> case it's likely a drive/media problem.  One way of verifying this would
>> be to use Unix utilities to read the tape, e.g. if it's the fourth file on
>> the whole tape, do this:
>> 
>> bash$ mt -f /dev/rmt/0ln rewind         (make sure you're at the start)
>> bash$ mt -f /dev/rmt/0ln fsf 3          (skip the first three files)
>> bash$ dd if=/dev/rmt/0ln of=FILE4.FITS bs=2880
>> bash$ echo $?
>> 0
>> bash$     

> I followed your advice with the following commands and results:

>> mt -f /dev/rmt/0ln rewind
>> mt -f /dev/rmt/0ln fsf 3           
>> dd if=/dev/rmt/0ln of=FILE4.FITS bs=28800
>   read: I/O error
>   18112+1 records in
>   18112+1 records out
>> echo $?
>   2

The manual page says error 2 means "an operation failed".  Not very
helpful.  It does point a finger at either the tape or the drive,
however.  Your system admin can check /var/adm/messages or /var/log/syslog
or whatever location is used for system errors, in case the drive
generated any around the time you saw the error.  If not, then it's likely
a bad tape.

>> bash$ tcopy /dev/rmt/0ln

I'm sorry, I gave the wrong device name.  For tcopy, which is a Berkeley
utility, you should use a different device name:

         tcopy /dev/rmt/0lnb

Otherwise tcopy only tells you about the first file and finishes, as you
saw: 

>> tcopy /dev/rmt/0ln
>   file 1: records 1 to 132: size 28800
>   file 1: record 133: size 2880
>   file 1: eof after 133 records: 3804480 bytes
>   eot
>   total length: 3804480 bytes

If you re-do the test with the Berkeley tape name (and *don't* use this
name for AIPS!), it will give you a more complete analysis of the tape,
including sizes.  This would be a clue as to whether the tape was full or
not. 

				- Pat