Setting the Block Size for a New Tape Archive

When you enter the Archive menu and format a new tape archive, the default block size matches the value in the Block Size field in the Format menu. Keep track of the block size value for each tape in case you need to reset the block size at a later time.

To verify the block size of your tape device:

1. In a command shell, log in as root.
2. Verify the block size of your tape device by typing:

   mt -f /dev/st<archive device number> status

Example:

mt -f /dev/st0 status

This command provides feedback similar to the following:

SCSI 2 tape drive:

File number=0, block number=0, partition=0.

Tape block size 65536 bytes.

Density code 0x40 (DLT1 40 GB, or Ultrium).

Soft error count since last status=0

General status bits on (41010000):

BOT ONLINE IM_REP_EN

Determining the Device Number for the Archive Device

If you receive an error message when verifying the block size, you may not be using the correct archive device number. Look in the software initialization configuration file to determine the correct number.

To determine the archive device number:

1. In a terminal, type:

   dlcfg

2. Look for the line that begins with the following:

   ClipMgtDeviceTape, /dev/st<archive device number>

   The archive device number should be listed on this line. If it is not, or appears to be incorrect, consult the administrator for your system.

Resetting the Block Size for an Existing Tape Archive

If you rebooted the machine or reformatted another archive with a different block size, you must reset the block size for your archive in the command shell.

To reset the block size of your tape:

1. In the command shell, log in as root.
2. Set the correct block size by typing:

   mt -f /dev/st<archive device number> defblksize <block size of your tape device>

   Example:

   mt -f /dev/st0 defblksize 4096

   The block size for your tape is reset and you can continue to archive to this tape.