Re: Qmail - huge performance increase

[Craig Sanders <cas@taz.net.au>]

On Wed, Jun 27, 2001 at 04:03:11PM +0200, Tomasz Papszun wrote:
> "/bin/ls | wc" has taken 1 (one) second. "ls | wc" lasted 3 minutes and 26
> seconds. Yes, near 3 and a half minutes!
> 
> This is because "ls" with additional information (e.g. file type, which is
> needed to colour a listing) needs more time to gather this information.
> I don't know what difference would be for reiserfs or xfs filesystems.

yep.

ls -l also takes a long time in large directories because it has to stat
each file to get the info about it.

i never bothered timing it, but in a directory with thousands of files
it is significantly faster to run this:

	ls -1S | head -30 | xargs ls -lS
        ^ -- numeral 1, not letter l.

than this:

	ls -lS | head -30



btw, in case you're wondering, i used to use commands like that to find the
largest 30 files in /var/spool/mail


craig

-- 
craig sanders <cas@taz.net.au>

Fabricati Diem, PVNC.
 -- motto of the Ankh-Morpork City Watch