FAT to HPFS File Restoration Results in File Corruption

• Microsoft LAN Manager, versions 2.0, 2.1, 2.1a, 2.2

SUMMARY

Upgrading from 3+Open and restoring backup tapes from FAT drives to HPFS drives can cause file corruption. This problem often is related to inadvertent use of Backup2 and Backman, not 3+Backup or 3+Restore.

SYMPTOMS

You discover evidence of file corruption after upgrading from 3+Open and using Backman or Backup2 to restore backup tapes from FAT drives to HPFS drives--even when directory structure is correctly restored.

If you restore to other 3+ Open machines you can copy the files correctly to the new server. This problem has been encountered using non-network tape drives and the 3Com GULP release of LAN Manager dated 9 June 1992.

This problem also occurs during ANY Backman or Backup2 restore to an HPFS partition on the server with the tape device, NOT just during an upgrade.

CAUSE

The corruption is related to the use of Backup2 and Backman, not 3+Backup or 3+Restore. File corruption occurs when you use Backup2 or Backman restore on an HPFS partition that resides on the same server from which the tape restore is being done. Corruption does not occur if you restore an HPFS partition that is not on the same server as the tape backup.

If you attempt to restore from tape to an HPFS partition on the same server, the data may not actually leave the box: all data transfer may be done internally on the bus because Backup2 and Backman are background applications. But 3+Backup and 3+Restore are not background applications, and data you restore using them goes out onto the net from the workstation that executes the program and then to the server.

This explanation is supported by the fact that when you restore to an HPFS partition on a different server the corruption does not occur even with Backman or Backup2, because in this case the data has to go out on the net.

RESOLUTION

Make sure you are using 3+Backup, not Backman or Backup2. If you must use Backman or Backup2, make sure the HPFS partition is on a different server than the tape backup.

Additional query words: 2.00 2.0 2.10 2.1 2.10a 2.1a 2.20 2.2 3backup 3restore

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Version : :2.0,2.1,2.1a,2.2
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