Environment:
Windows Server 2008
1 x MOSS WFE Server
1 x MOSS APP Server
1 x SQL Server
I recently had to troubleshoot an environment where SharePoint backup jobs were becoming stuck on the Search related databases. The backup status would stay on the initializing phase and wouldn’t go past 50% for these databases and eventually the whole backup sequence would terminate or we’d have to terminate it manually. Checking all the event and diagnostic logs didn’t yield any helpful clues except for the generic event ID’s 6398, 7076, and 6482 which seemed totally unrelated at the time.
Upon closer inspection and some more sleuthing it was discovered that the incremental index jobs were scheduled and running during the backup jobs. Apparently, the backup job was getting confused and got tripped up on this fact. So we scheduled the incremental crawls to run outside of the backup window and everything turned out ok!
The SharePoint Swiss Army Knife 
Can you provide some more details on this?
Same here. The backup is fully blocked when the search-indexer is running.
Its critical to avoid “collisions” of both services or you get deadlocks. Each service its waiting for the other to complete … Really buggy 🙂
Greetings
Eric
In regards to more details, if it will help anyone out there with this issue.
I believe to adjust your INDEXING, you must go to your Search Service Application; then, click on Edit Content Sources and adjust your crawl schedules to not conflict with your backups.
Good luck.