[nylug-talk] Ext3 Disk Reservation and Defaults -- WAS: extfs journalling percentage

[Peter C. Norton]

On Thu, May 29, 2008 at 10:00:30AM -0400, Bryan J. Smith wrote:
> > The default of 5% seems like a reasonable value as far as I can tell.
> 
> The potential benefits of reserving 5% outweigh the storage loss.  It's
> all about cost v. risk.

The benefit of enough megs to do some necessary in is not in question,
but 5% is, these days, way overkill.

Reserving 5% of a 20mb disk makes sense. If you have to fix something,
you need enough space for root to log in, and be able to make a file
even when a regular user can't.

However, on a 1TB filesystem, I can't think of a reasonable thing that
root needs to do that requires 50gb of space that could otherwise be
usefully employed on that filesystem. .1% seems more reasonable in
that case, though possibly still excessive.

It also reduces confusion if you don't reserve 5%, since you'll no
longer see that a filesystem is 104% fill.

-Peter

-- 
The 5 year plan:
In five years we'll make up another plan.
Or just re-use this one.