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Summary



DPX reports logical end of tape before the tape's rated capacity has been reached.

Symptoms



The following message is printed in the job log:

SNBDBR0701W 4440: dm_process_send_backup_data_reg: Encountered Logical End Of Tape.

 



Resolution



DPX does not refer to the user-defined "capacity" field to determine when a tape is full. Instead, DPX writes data to the tape until it receives a signal from the tape drive indicating that it has reached the End-Of-Tape.

The following are possible causes for the "Encountered Logical End Of Tape" message:

  1. The tape is really full, but hardware compression is not enabled. In DPX 2.1.X, to verify this look at the Data on Media field for this tape in the Media Reports screen of DPX. Check if the tapes are only reaching their uncompressed capacities. In DPX 2.2.x or higher, verify this by looking at the Total_Bytes(KB) field in the Media Volume Report. Note: Hardware compression is enabled/disabled generally with a jumper or a toggle switch. Please contact your Hardware manufacturer for the procedure on how to verify/set these.
  2. A SCSI or Fibre Channel error occurs during the backup. Look in the system messages at the time that the end of tape is reported. If there are messages indicating a SCSI or Fibre Channel problem, consult your hardware vendor.
  3. A tape is defective. If one tape reproducibly fills before the others, it indicates that this piece of media is defective. Also when tapes are written to for longer than what the manufacturer recommends, an excessive number of rewrites can occur, causing a reduction in performance and tape capacity. Use a new tape to test compression and confirm that the media is the correct type for the tape drive.
  4. The tape drive may need to be cleaned. A buildup of oxidation and debris on the tape heads can cause soft/hard write errors and eventually could cause damage to the tape media and tape drive. Clean the device as per the manufacturer's recommendation and replace the cleaning tape when necessary
  5. If hardware or software compression is being used, the tape drive may not write to the tape's compressed capacity because files being written are already compressed (i.e., zip, rar, gzip) or are not very compressible (i.e., pdf, jpeg, mpeg, avi, mp3). With files that can not be well compressed further, the tape drive will reach LEOT somewhere between the tape's native capacity and short of its compressed capacity.