Chapter 7 Troubleshooting Guide
Troubleshooting Suggestions
The method of performing the backups can also be a factor in “slow” backups. Data sent to the tape drive over a network connection and delays in data transfer over a network connection can cause backups to slow down.
1Perform write/read test with diagnostic software. This ensures a test of the connection between the tape drive and SCSI controller and removes the network data transfer and the backup software from the diagnosis. The write/read test will overwrite data on the tape.
2When the test finishes, determine the megabyte per second data transfer. The resulting calculation shows the tape drive performing at an acceptable rate.
3If you believe that the write/read transfer is slow even after using the diagnostic software write/read test, use the Quantum Tape Diagnostic software to perform a trace buffer retrieval. Send the file to Customer Support, so that the state of the SCSI bus can be determined.
4If the diagnostic write/read test transfer rate is acceptable, but backups still seem to be “slow,” it may be attributed to the number of files and the average file sizes that are to be backed up. These factors can have a significant effect on the backup performance. Backups where the average file size is less than 200 Kbytes are slower than backups where the average file size is greater than 200 Kbytes. Obtain backup log files to determine number of files and average file size.
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