Error -24201, Chunk checksum didn't match?

[BiG]

Anyone else encountered:

 

 

 

"Trouble matching 'volume name' on 'computer name' to 'backup set name', error -24201 (chunk checksum didn't match)."

 

 

 

I been getting it consistently, under these conditions. It is almost always on the third tape of a backup set. The backup set created for a Backup Server where I have it set to back up my clients once a day using Retro 5.0.205. It has happened both before and after the driver update. The clients are a mix of OS 9.x and OS 10.1.x, all running the most current client. The server is a G3/266 desktop, running OS 9.2.2, backing up through an adaptec 29160 to a Sony 35/70GB AIT.

 

 

 

I'd hoped I could limit the problems cause to one client, or one type of client, but can't, the trouble matching will begin after backing up either a OS X or OS 9 box. I have tried to create new backup sets, it still happens, always somewhere during the third tape. yes, it is a different tape each time. I've also tried a complete reinstall, doesn't help. It seems to only happen when Retrospect is set to act as a backup server. Ereasing the third member of the set helps, but only to a point, because eventually the trouble matching error happens again.

 

 

 

Any help, suggestions or sympathy would be appreicated.

[AmyJ]

From the Knowledgebase:

 

 

 

Retrospect's catalogs are really databases that track the files backed up to your backup sets. To detect corruption, should it ever occur, Retrospect saves each block of data in its catalogs with a checksum, a saved calculation based on the block of data, that allows Retrospect to check data integrity later when it reads the data back. Each time it reads data from a catalog, Retrospect quickly verifies that the data is valid by comparing it with the stored checksum. Should a catalog become damaged or corrupt, you may see one of the following errors:

 

 

 

Macintosh Retrospect errors:

 

 

 

-24203 not a chunk file or badly damaged

 

-24202 chunk file map missing/damaged

 

-24201 chunk checksum didn't match

 

 

 

Windows Retrospect errors:

 

 

 

-641 chunk checksum didn't match

 

-642 chunk file map missing/damaged

 

-643 not a chunk file or badly damaged

 

 

 

These all basically mean that Retrospect has detected that the catalog file is corrupt or damaged. You will need to rebuild it, or restore it, if you have it backed up somewhere.

 

 

 

How does this happen? Typically these errors can been seen if there is a crash or power failure while Retrospect is updating a catalog file. You can also see these errors if you have a configuration problem that is causing data corruption on your hard disk or network. If you have only see this error once, we recommend making a note of it, and moving on. If you have seen it multiple times, then you should work to figure out the source of the problem. Try saving your catalogs onto a different hard disk (we have seen obscure problems with data corruption being caused by specific hard disks). If the problem does not follow your catalogs to the new hard disk, consider the original hard disk suspect. It may be that the drive is corrupting other data as well. Consult your drive vendor's documentation, or contact the vendor for assistance.

 

 

 

If the problem follows your catalogs to another hard disk, we recommend changing the computer you are running on, if possible. We have, in very rare cases, seen problems with computers that could not be easily quantified, that consistently led to chunk checksum errors on catalogs. These could be caused by RAM, ATAPI or SCSI bus configuration issues, USB or FireWire or IEEE 1394 conflicts or driver issues, or other failing hardware. These are terribly hard to troubleshoot; if things work well on another computer, we recommend switching the backups to that computer, and investigating what might be causing the corruptions on the original computer. Obviously this would be very complex to do. You may end up being satisfied with having your backups working again in their new configuration. It is up to you.

 

 

 

However you troubleshoot chunk checksum errors, the bottom line remains that they are caused by Retrospect's data becoming corrupt. Retrospect itself is not corrupting the data, so your troubleshooting efforts should focus on the other variables, as noted above.