Improper shutdown of system / Fragmentation Problems / Boot
rpratt1950 at earthlink.net
Wed Jun 9 12:14:58 PDT 2004
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!
> 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
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