ext4 won't mount - fsck required - 2nd fsck in less than a week
 

Hello,

As the subject says, we have a 15 TB fsck drive that won't mount with these errors:

Sep 9 20:02:20 narf kernel: EXT4-fs (dm-9): ext4_check_descriptors: Inode bitmap for group 3200 not in group (block 4161027887)!
Sep 9 20:02:20 narf kernel: EXT4-fs (dm-9): group descriptors corrupted!

We did a proactive fsck on Tuesday of last week because it was starting to give filesystem errors. It ran through and mounted fine.

The filesystem lives on a large equallogic SAN spread across 36 drives. Could this be something with the physical layer or is it not abnormal to have to run multiple rounds of fsck to fully fix an issue?

Normally issues should be fixed when fsck says there are.
Sometimes it asks for multiple runs. If not it should be clean.

THere is a possibility that the equallogic array has an issue. However IIRC you can see that in the logs. If you are unsure please check with Equallogic. They can get more info from the diagnostics report.

It might be that there was a crash?