Chronic Miscompare problems

[derrickfogle]

4 out of 9 now on miscompares:

 

 

 

4/4/2002 11:55:02 PM: Copying Derrick on Backup…

 

4/5/2002 1:14:42 AM: Comparing Derrick 04 on Storage2…

 

File “DerrickDaily”: miscompare at data offset 531,525,632, path: “Derrick/DerrickDaily”.

 

4/5/2002 1:19:28 AM: 1 execution errors.

 

Completed: 1 files, 2.3 GB

 

Performance: 53.4 MB/minute (28.3 copy, 473.5 compare)

 

Duration: 01:24:26 (00:00:02 idle/loading/preparing)

 

 

 

The slow copy times reported in the "Horribly slow Duplicates" thread ( http://support.dantz.com/ubbthreads/showflat.php?Cat=&Board=Desktopworkgrupx&Number=3367&page=2&view=collapsed&sb=5&o=0&fpart= ) seem to be associated with the 'miscompares'. The other big Duplicate (2.7Gb) had no compare problems, and ran at nearly 300Mb/min.

 

 

 

These backups aren't any good, are they?

[derrickfogle]

6 out of 11 miscompares now:

 

 

 

File “DerrickDaily”: miscompare at data offset 116,196,507, path: “Derrick/DerrickDaily”.

 

File “MarkDaily”: miscompare at data offset 1,484,386,304, path: “Mark/MarkDaily”.

 

 

 

I've ran independent tests on the hardware and everything tests fine. These drive-to-drive storageset file copies are the only ones having problems - all the other backups are working fine. Why can't retrospect Compare these files successfully?

[derrickfogle]

7 out of 13 miscompares now. I'm glad no one else has this problem.

[derrickfogle]

8 out of 15 now. Seems very random, not always the same destination drive (which tests fine), not always the same file.

 

 

 

The copy is always horrendously slow when this happens (10-20Mb/min). Copying the files in the Finder never produces a slowdown.

 

 

 

I installed the update today, but I doubt it will address this problem. It really does seem like a retrospect problem, though, and not a hardware problem. Retrospect's "Copy" is the *only* place where this occurs; the drives have been tested several times now, copies in the finder never have a hitch.

 

 

 

If nothing else, this is a good place to document all my problems for when I call tech support.

[pchernoff]

After suffering from chronic miscompare problems, I tried changing SCSI card, cable and computer. It turns out that my DLT machine was malfunctioning and I needed to return it for repairs.

[derrickfogle]

10 out of 18 now - I've added another computer to the laptop group which operates this way.

 

 

 

My backup server is an iMac/400/128/OSX with two attached QPS M3 60Gb HD's. I've ran fairly extensive tests on the hardware - it always passes. The drives do have a history of locking up occasionally; that's happened once in the 2 weeks so far I've been running 5.0. But there are 2 drives that get used (on alternate days) and 3 different files that get duplicated every night. The problem is not specific to one drive or one file. One day a duplicate will go slow and miscompare; two days later the same file (with just a couple of very minor incremental changes) to the same drive will work.

 

 

 

I haven't ruled out the hardware, but Retrospect is the *only* app that appears to have problems with the hardware. I'm sure that complaining about this will get my hardware dropped into the 'unsupported' bin like the adaptec cards, but that's a pretty lame response to an application-specific problem.

[derrickfogle]

11 out of 19 as of 4/11/02 (my destination volume filled up, so the other 2 didn't run).