This problem has really got me confused - any suggestions would be VERY much appreciated.

I recently installed a Certance Travan 20 tape drive, connected to a Tekram DC-315U SCSI card. The hardware installation appears to have gone fine. I checked this by running a utility program supplied by Certance (SGTape21) which reported that the tape drive was working properly. I recompiled my kernel (I'm running Fedora core 2) to include support for the SCSI card without any problems.

However, when using the tape drives to do backups, I'm finding that approximately 5% of the backed-up files do not verify when compared with the source files. If I repeat the backup operation (maybe including other directories in the backup for example) I find that the SAME files (repeatedly) fail on the verify step. These files aren't system files that you might expect to change during the backup process, instead they are files like Word files (.doc), Powerpoint files (.ppt), Quicktime movie files (.mov). Plain text files seem never to give any problems. I have performed the backup s in various ways:
1) Using 'tar' from Linux (Fedora core 2)
2) Using Tapeware software under Linux (supplied with the Certance drive)
3) Using Tapeware software under Windows ME (I have a dual boot system)
However I get the same problems with the same files whichever method I use. (Tar-ing to a file instead of to the tape drive works okay, but tar-ing to the tape drive leads to the verify errors).

What really confuses me is why the problem should be specific to certain (static) files. Any ideas would be much appreciated. (I've been hassling Certance technical support on this, they've not been able to help me yet).

Thanks,

Tim

Hi and welcome to LQ

Just a thought, does someone have these files open on a pc or laptop somewhere? It may be that they are in use and are locked..... Are they permanently displayed on a screen somewhere maybe?

Thanks for the suggestion. However, no the files aren't open elsewhere.

I tried to debug this by restoring a few of the reportedly corrupt files and then comparing them with the originals. This isn't so straight-forward because none of the failed files are plain text. However I compared the original and restored files using "diff" and the "-a" option (treat the files as plain text even if they aren't) and found that there were differences in the amount of white space in certain lines. (I'm not sure what the output of "diff -a" really is, whether all non-ASCII characters are displayed as white space.)

Any other suggestions of things to try to diagnose the probem would be much appreciated!

Tim

Problem finally solved!

For the record: originally I had installed a combination of a Tekram DC-315U SCSI adapter and a Certance Tapestor20 tape drive. A utility program that came with the SCSI card reported that it was installed correctly, and a Certance utility program (SGTAPE21) reported that the combination of the SCSI adapter and the drive were functioning correctly. However, I kept finding a lot a verify errors (confusingly, for the same files), both when running under Linux and Windows.

To solve the problem, I replaced the Tekram SCSI adapter with a cheap Adaptec card. Since then, I've not had any more errors.

I don't know if there was a manufacturing problem with the Tekram card (if so, why did the utility program report it was functioning properly?) or if there's some fundamental inconsistency with the combination of the Tekram DC-315U SCSI adapter with the Certance Tapestor20 drive (if so, why did Certance's utility program SGTAPE21 report that things were functioning correctly, when they weren't?). All I know is that having changed the SCSI card, backups now work correctly.