heavily fragmented file system.. How to defrag it on-line??

[Theodore Ts'o]

On Wed, Mar 03, 2004 at 08:06:16PM -0700, Andreas Dilger wrote:
> On Mar 03, 2004  18:36 -0800, Guolin Cheng wrote:
> >  Then How can I figure out whether the files are defragmented? Because the
> > file system's read/write speed is greatly slow down ( about 8-10 times
> > slower in extreme cases). 
> 
> I think there was a tool which would map your files for you, using the FIBMAP
> ioctl, but you could also use debugfs "stat" to tell you the block maps of
> particular files.

E2fsprogs 1.35 comes with a program "filefrag" that will tell you how
many extents a particular file has.

						- Ted