Subject: Re: More on sorted I/O requests
To: Gregory McGarry <g.mcgarry@ieee.org>
From: Wojciech Puchar <wojtek@chylonia.3miasto.net>
List: tech-kern
Date: 06/28/2002 12:05:45 
> /storage/scratch
> $ dd if=/dev/zero of=bigfile bs=1024k count=200
> 200+0 records in
> 200+0 records out
> 209715200 bytes transferred in 8.326 secs (25187989 bytes/sec)
> $ rm bigfile
> $ df
> Filesystem  1K-blocks     Used     Avail Capacity  Mounted on
> /dev/wd0a       63248    31634     28451    52%    /
> /dev/wd0e      253615    83672    157262    34%    /var
> /dev/wd0f     1465278   372914   1019100    26%    /usr
> mfs:123         31727     2175     27965     7%    /tmp
> /dev/wd0g     1018329    56420    909297     5%    /home
> /dev/wd0h    12766536 11862460    265748    97%    /storage

doing sync few times after rm solves the problem.

it's not I/O request queue problem, just filesystem. delayed free speeds
up things