[ILUG] hdparm

[Paul Kelly]

Keith Hyland wrote:
> im trying to get my home server (suse6.3) to go to sleep..
> i have set hdparm -S 240 for the three drives hda hdc hdd
> hda keeps starting up again.

Lots of things in Linux will access the hard disk on an automated basis
- and not just file writes either. Any time a file is access the 'atime'
stat of that file will be written back to disk. If you have cron running
at all for example, it will examine /etc/crontab among other files every
minute.

To combat this, you can mount your ext2/3 filesystems with the 'noatime'
option. You should also take a look at http://noflushd.sourceforge.net/
which helps delay disk writes further than would otherwise be done.

> /var/log/messages dosent show anything that seems to be doing it.   altough
> there is an entry every 20 mins:
> 
> Nov 24 03:50:27 oak -- MARK --

Ummm. That message alone is enough to cause a write to a file which, by
default, will be flushed to disk within about 30 seconds. Check your
init scripts that start syslogd and stop it being passed the -m option.

Paul.