I created two partitions on a 1.5 TB drive, the first was 1 TB, the latter was the remaining .5 TB. Both were formatted as ext3. I don't mind the automatic filesystem checks occurring every so often, so I never bother configuring the frequency of it. What I found odd was that it decided to make the automatic check occur every 39 mounts for the 1 TB, and 27 mounts for the .5 TB partition. I attempted to look in the man pages as well as various forums, but I couldn't find any mention about how it determines the frequency for file system checks. I assume it is a simple formula, so does anyone know what it is?
What makes ext3 determine how frequently to perform file system checks when no options are specified
ext3
Best Answer
The good thing about linux is the source is always somewhere. You can download or view the base e2fsprogs sources on kernel.org. This can also depend on your specific version and distribution though...
From current code it looks like it's some value added to 20 based on the UUID of the partition, if you have
enable_periodic_fsck = 1
in your mke2fs.confmke2fs.c
mke2fs.h
Always good to see the words 'kludgy' and 'hack' in code =)