Quadratic fsck

[Patrick O'Callaghan]

On Sun, 2008-07-27 at 12:32 -0700, Chuck Forsberg WA7KGX N2469R wrote:
> Forced fsck operations on huge filesystems (500GB) are
> taking a very long time during bootup.  Some typical
> situations:
> 
> /dev/sdb6            448936380 399105212  27026504  94% /w
> /dev/sdc2            500028036 444954060  29674008  94% /v
> /dev/sdc1            461404200 305735808 132230364  70% /y
> 
> How can I reduce this time?  Would converting these to ext4
> speed up fsck?  Is converting to ext4 an option yet?
> 
>  Can something be done in the background
> on a mounted file system to check it or at least minimize the
> time it takes to run fsck on it?

Are you running fsck with every boot? In ext3 this is usually
unnecessary. Most boots use the journal, which is very fast. I have a
500GB filesystem that's over 60% full, and is on an external USB disk so
it's not particularly fast, but the check time is only a few seconds.

Use tune2fs to adjust the number of mounts to wait before using
auto-fsck.

poc