On Thu, Jun 24, 2004 at 12:23:23AM -0500, Sam Williams wrote:
I've run ext3 filesystems for the last few years and I've never seen this question answered..... If a system shutsdown hard, even with journaling is it at all necessary to run e2fsck?
Theodore Ts'o answer:
It's best to just always run e2fsck. Yes, you can just simply mount an ext3 filesystem after a crash, since the kernel has code to run the journal; this is necessary if the root filesystem is a journalled ext3 filesystem. However, it's better to let userspace (i.e. fsck/e2fsck) take care of things from that point, for the following reasons:
1) E2fsck will run the journal automatically, and if the filesystem is otherwise clean, it skip doing a full filesystem check.
2) If the filesystem is not clean (because during the previous run the kernel noticed some filesystem inconsistencies), e2fsck will automatically do a full check if it is necessary.
3) If you have multiple disks, fsck will run multiple e2fsck processes in parallel, thus speeding up your boot sequence than if you let the kernel replay the journal for each filesystem when it tries to mount it, since then the journal replays will be done sequentially, instead of in parallel.
The bottom line is that the all of the default major distributions are doing the right thing, and they are running e2fsck on ext3 filesystems for a good reason.
So in answer to your question, no it is not ***necessary*** to run e2fsck, however, it is a good idea, and it will not slow down your boot time any to do so, and in fact if you have multiple hard drives, it will likely speed things up.
- Ted
