On Wed, 25 Aug 1999, Poor Mike wrote:
>I use RH6 and my system sometimes (once a week) says me this:
>"/dev/hda1(my root) has reached maximal mount count, check forced"
The ext2 file system counts how many times it is mounted. It also maintains a
mount count limit, and forces an fsck (file system check) if the mount count
exceeds that limit. The theory is that it's god to check the file system every
so often, just in case some undetected error has crept in, and doing so every
so many mounts is one easy way to enforce such a policy. It also, by the way,
maintains another limit, i.e. the amount of time which has passed since the
last fsck, and forces one if it is mounted after that much time has transpired.
You can see these values via dumpe2fs, and you can see/change these values via
tune2fs. The defaults are 20 mounts and 6 months.
>after several minutes of checking something like this:
>"(1,2% non-contigious)"
This is not an error ... it's just an interesting piece of information. It's
telling you how much of the data in that file system is not strictly
contiguous. 2% is not bad at all.
A file is contiguous if all of its disk blocks sequentially follow one another
on the disk. This kind of layout would be ideal, as it would maximize system
performance since there would be a minimal number of disk head seeks (moves),
each of which takes a significant amount of time to perform. In practice, you
can never get 0% discontiguity for every file within the file system because
the file system also contains a lot of metadata (file system structure
information) like the directory (map from file name to i-node number), the
i-node (file) table, the used/free i-node bit map, the used/free disk block bit
map, etc. In addition, as a file is extended, each new block must be assigned
from wherever the next free block can be found (which is not necessarily
anywhere near where the rest of that file is).
--
Dave Mielke | 856 Grenon Avenue | I believe that the Bible is the
Phone: 1-613-726-0014 | Ottawa, Ontario | Word of God. Please contact me
EMail: [EMAIL PROTECTED] | Canada K2B 6G3 | if you're concerned about Hell.
