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How to dump the tape header on Windows

Article: 100021814
Last Published: 2009-01-19
Ratings: 1 1
Product(s): NetBackup & Alta Data Protection

Problem

How to dump the tape header on Windows

Error Message

io_read_media_header: block read is not a NetBackup or Backup Exec media header

Solution

The above bptm error can be seen when reading tapes, generally during whenattempting to import tapes.  This can occur when using encryption devicesto write the backup, and then later importing the tape, either in a differentNetBackup environment, or in the same environment after disabling the encryptiondevice.  
To dump andread the tape header, there is a utility called nt_ttu, located in thefollowing directory:
<installpath>\Veritas\volmgr\bin
 
First, loada tape into a drive using robtest (if drive is robotic), and then run nt_ttu as shown in the example below. Note the Tape Path defined for thedrive in question.  In this example " tape1".
nt_ttu -f tape1
Welcometo nt_ttu, h[elp] or ? for help.
DataBuffer Initial Address - 8f4000
nt_ttu>o   (opens the drive)
nt_ttu>i c=rew   (rewinds the tape)
cmd= rew
nowrewinding the tape
nt_ttu>r b=1024 (this will read the first 1024 bytes)
nt_ttu>d (dumps the bytes read above to the screen)
 
Example:
00000000:564f4c31 444f554e 42550000 00000000 00000000
00000020:00000001 0000000c 00000000 00000000 00000000
00000040:00000000 00000000 00000000 00000000 00000000
00000060:00000000 00000000 00000010 00000400 00000000
00000080:00000000 00000000 00000000 00000000 00000000
00000100:00000000 00000000 00000000 54684973 20497320
00000120:41204250 20744170 45206845 61446572 00000000
00000140:00000000 00000000 00000000 00000000 00000000
00000160:00000000 00000000 00000000 00000000 00000000
00000180:00000000 00000000 00000000 00000000 00000000
00000200:00000000 00000000 00000000 00000000 00000000
00000220:00000000 00000000 00000000 00000000 00000000
00000240:00000000 00000000 00000000 00000000 00000000
00000260:00000000 00000000 00000000 00000000 00000000
00000280:00000000 00000000 00000000 00000000 00000000
00000300:00000000 00000000 00000000 00000000 00000000
00000320:00000000 00000000 00000000 00000000 00000000
00000340:00000000 00000000 00000000 00000000 00000000
00000360:00000000 00000000 00000000 00000000 00000000
00000380:00000000 00000000 00000000 00000000 00000000
nt_ttu>exit (exits nt_ttu)
 
Parts of theresulting output need to be translated from HEX to ASCII:
00000000:564f4c31 444f554e 42550000 00000000 00000000
Translatesto:  VOL1DOUNBU
If this is aNetBackup formatted media, VOL1 will always be seen as the first 4 characters..The remaining 6 characters are the actual NetBackup Media ID, in thiscase:  DOUNBU
 
This nextpart of the HEX dump defines the media as "BP" (Backup Plus is is the originalname of NetBackup):
00000120:41204250 20744170 45206845 61446572 00000000
Convertingthe above HEX to ASCII shows:
ThIs Is A BPtApE hEaDer
 
NetBackupmust read the above information to consider the tape a valid NetBackup tape.
 
An onlineHEX to ASCII translator can be found here:
https://www.paulschou.com/tools/xlate
Note:Veritas is not affiliated with the above web site in any way and is notresponsible for its content.
 

 

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