A server I had to work on over the weekend has several Very Large Filesystems – checks take about an hour, and every hour of downtime means angry customers.
The date was being reset badly, and making EXT3 throw an inconsistency check, because the time of the last mount was after the current time. It’d set the “filesystem has errors” bit on the filesystem, making a disk check mandatory.
Eventually, I reset the filesystem’s error bit, so that it would ignore the trivial error:
debugfs -w -R 'set_super_value status 1' /dev/diskname
tune2fs -T now /dev/diskname
Status 1 is “clean, no errors”
Danger, Will Robinson, if you’re doing this to bypass serious errors, but in this trivial case, it saved several hours of downtime.