Re: tracking down disk spinups.

From: Dave Jones
Date: Mon May 14 2007 - 16:47:14 EST


On Mon, May 14, 2007 at 04:28:35PM -0400, Rob Landley wrote:
> On Monday 14 May 2007 2:57 pm, Dave Jones wrote:
> > Why did the kernel ignore what I told it to do ?
> > I'm sure it thinks it knows better than me for a reason, but
> > I'd like to know what it is.
>
> Remount doesn't switch filesystem drivers, it tells the existing filesystem
> driver to accept new flags and/or a new option string.

yes, I had misinterpreted what 'remount' did. I thought behind the scenes
it actually did a umount/mount.

> To switch drivers you have to umount the old sucker and mount the new one.
> (The idea of handing off consistent cache data from one mounted filesystem
> driver to another... Ouch.)

a umount would purge the cache, but that's irrelevant given it doesn't
work that way.

Anyways, I rebooted after s/ext3/ext2/ on my fstab, and found things
hadn't really got any more obvious what was going on.
Instead of 'kjournald' writing stuff out, now it's 'pdflush'.

*has sudden brainwave*

Ahh, it's doing atime updates. Duh.

Dave

--
http://www.codemonkey.org.uk
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