Re: Is there a way to keep the 2.6 kjournald from writing to idle disks? (to allow spin-downs)

[Felipe Alfaro Solana <felipe_alfaro@linuxmail.org>]

On Sun, 2004-01-25 at 19:29, Lutz Vieweg wrote:
> Hi everyone,
> 
> I run a server that usually doesn't have to do anything on the local filesystems,
> it just needs to answer some requests and perform some computations in RAM.
> 
> So I use the "hdparm -S 123" parameter setting to keep the (IDE) system disk from
> spinning unneccessarily.
> 
> Alas, since an upgrade to kernel 2.6 and ext3 filesystem, I cannot find a way to
> let the harddisk spin down - I found out that "kjournald" writes a few blocks every
> few seconds.
> 
> As I wouldn't like to downgrade to ext2: Is there any way to keep the 2.6 kjournald
> from writing to idle disks?
> 
> I cannot see a good reason why kjournald would write when there are no dirty buffers -
> but still it does.

Have you tried playing with the laptop-mode patch? It's already in the
-mm kernel tree from Andrew Morton. I've been playing with it a little
(just a few minutes) and seems keep the disks spun down for some time.
However, I haven't been able to get it suit my needs, since I use apps
like Evolution which are continuously writting to the disk.

If you are willing to play with it, I recommend you downloading the
latest -mm patch from http://www.kernel.org, untar the sources and then
read Documentation/laptop-mode.txt.