On Fri, Oct 05, 2007 at 04:02:21PM -0400, Dave Jones wrote:
Right now we're running readahead early way too late.
At a time when we've just sat doing no IO at all for 10
seconds whilst (amongst other things) we waited for a
DHCP lease. We're also running it at a time when
we're competing for disk bandwidth with other processes.
The result is that disabling the service completely shows
no change in boot time at all.
http://www.codemonkey.org.uk/junk/bootchart-before.png
Moving the readahead_early service to start really early
wins back 4 seconds of boot up time.
http://www.codemonkey.org.uk/junk/bootchart-after.png
Please, define "really early".
I have (workstation, F7, 2GB RAM):
- /etc/rc5.d/S01readahead_early
- /etc/readahead.d/custom.early
(generated by readahead-collector from F8)
- only one readahaed list
(merged .early and .later lists)
results (readahead on/off):
http://people.redhat.com/kzak/readahead/f7-on.png
http://people.redhat.com/kzak/readahead/f7-off.png
.. so nothing useful :-(
Any reason not to change this for F8 ?
I don't believe that readahead is able to really improve Fedora boot
time.
Karel
--
Karel Zak <kzak(a)redhat.com>