filesystem: 12h to delete 32GB of data

[Olivier Mueller]

Hello,

$ df -m ; date ; rm -r templates_c ; df -m ; date
Filesystem  1M-blocks   Used Avail Capacity  Mounted on
/dev/da0s1a       989     45   864     5%    /
/dev/da0s1f    128631 102179 16160    86%    /usr
[...]
Wed May  6 00:23:01 CEST 2009

Filesystem  1M-blocks  Used Avail Capacity  Mounted on
/dev/da0s1a       989    45   864     5%    /
/dev/da0s1f    128631 69844 48496    59%    /usr
Wed May  6 12:21:02 CEST 2009


-> it took about 12 hours to delete these 30GB of files and
sub-directories (smarty cache files: many small files in many dirs).
It's a little bit surprising, as it's on a recent HP proliant DL360 g5
with SAS disks (Raid1) running freebsd 6.x
( /dev/da0s1f on /usr (ufs, local, soft-updates) )

Surprisingly, cpu load remained quite low during the operation (apache
stayed responsive).  Is it a known problem on this kind of hardware or
something related to the filesystem? Is there a way to improve this?
Even on my $500 PC with IDE disks this goes quicker... :)

I checked
http://www.freebsd.org/doc/en/books/handbook/configtuning-disk.html but
I'm not sure if this would help in this case. Any suggestion how I can
"fix" that? 

Regards,
Olivier