Re: Qmail - huge performance increase

[David Bishop <dbishop@micron.com>]

And on an Ultra-60 running Solaris 7 w/UFS:

bash-2.04$ time /bin/ls | wc
   63975   63975 1971245
 
real    0m2.213s
user    0m1.160s
sys     0m0.890s
bash-2.04$ time ls | wc
   63975   63975 1971253
 
real    2m19.965s
user    0m1.490s
sys     0m16.340s
bash-2.04$

Sped it up "just a little bit" :-)

On Wednesday 27 June 2001 07:03, Tomasz Papszun wrote:
> On Thu, 21 Jun 2001 at 13:25:17 +1000, Craig Sanders wrote:
> > On Thu, Jun 21, 2001 at 01:45:23AM +0800, Jason Lim wrote:
> > > SO... by increasing conf-split to 97 (from the default of 20
> > > something afaik), each directory ends up only having a hundred or so
> > > files. Doing "ls" now is far speedier.
> > > [...]
> >
> > this is actually a well-known limitation of ext2fs and similar
> > file-systems - as soon as you get more than a thousand or so files in a
> > directory, performance takes a nosedive.
>
> BTW, a tip: if you've got "ls" aliased (for instance as
> 'ls --color=auto -F') then you can shorten this long execution of "ls".
> Just issue "/bin/ls" instead of "ls". The difference is very big. It can
> be as 1:200 (yeah!). I've just done a comparison in a directory
> with > 33000 files.
>
> "/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.
>
> Hope it helps a little :-) .

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dbishop@micron.com