Improper shutdown of system / Fragmentation Problems / Boot logs

[Randy Pratt]

On Wed, 9 Jun 2004 14:36:52 -0400
Bill Moran <wmoran at potentialtech.com> wrote:

> Randy Pratt <rpratt1950 at earthlink.net> wrote:
> 
> > On Wed, 9 Jun 2004 07:05:43 +0800
> > Robert Storey <y2kbug at ms25.hinet.net> wrote:
> > 
> > > 
> > > > I am kinda new to FBSD, still kinda learning stuff. Anyway, when my
> > > > system boots i see all kinda fragmentation information. How do I
> > > > correct this? Any good reading material? 
> > > 
> > > FreeBSD will defragment itself without any action from the user.
> > > However, defragmentation requires some blank space, and (ideally) you
> > > should not let any partition get more than 80% full. You can check on
> > > that with "df -h":
> > 
> > I've been running partitions well over 90% for over six years on
> > FreeBSD and have not seen any problems with doing so.
> > 
> > Do you have a FreeBSD documentation reference for that 80% figure?
> 
> man tunefs
> 
> See, in particular, the section on the -m option, which describes (in brief)
> the known performance problems and how FreeBSD reacts.

My minfree space is at the default of 8% and the man page says this
is space held back from normal users.  Is that 8% also held back
from the df output?  I'm thinking that it is since I've seen posts
where users have greater than 100% showing in their df output.

I was interpreting the 80% number being applied to the numbers
shown by df.  If its 98% as shown by df 
(8% minfree + 2% more = 10% of total disk capacity), then that isn't
too bad.  I think I'm under that most of the time.

Would the total disk size start to come into play at some point?
10% of an 8G disk is a whole lot smaller than 10% of a 200G disk.

Thanks for the pointer too!

Best regards,

Randy

> Robert's numbers aren't quite right.  The point at which performance starts to
> suck is 90% full.
> 
> You won't have any _problems_, it's just that performance will degrade,
> according to the man page, up to 3x slower.
> 
> -- 
> Bill Moran
> Potential Technologies
> http://www.potentialtech.com


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