Re: md /tmp and async mounts

On Sun, Jun 04, 2006 at 08:03:16AM +0300, Giorgos Keramidas wrote:
> ...
> >> I think if you don't have any swap configured, a swap-backed md
> >> will be no worse off than a memory-backed one would.

I'd be rather strongly incline dto agree with that, FWIW.

> > Yeah, it's kind of a poorly chosen name.
> 
> Should we still revert the default from using -M for tmpmfs="YES" and
> varmfs="YES" in rc.conf?

Ever since /usr/src/etc/rc.d/tmp rev. 1.35 (creation of $tmpmfs_flags),
I have used the specification to avoid -M.  I'd recommend that the
default ought not be -M.

Since Kris posed his query re: -o async, I changed my $tmpmfs_flags to
include it -- both for 6-STABLE and for -CURRENT -- on my laptop, where
I track each of those branches every day that there's a change to the
corresponding source tree.  (Well, save for last weekend, when I was
off-Net for a couple of days....)

While I haven't seen a noticable performance improvement from -o async,
I've certainly not seen any negative impact at all.

FWIW, the one other tweak to $tmpmfs_flags I find useful is to adjust
the inode density to reflect a larger number of (smaller) files in the
/tmp file system.  On the laptop, where the daily buildworlds (and
occasional builds of mozilla...) tend to be the most strenuous workout
it gets, -i4096 seems to be OK.

For CVS servers (which the laptop can be at times, though I prefer to
use more dedicated resource to that sort of task), I find -i1024 to be
preferable.  (Recall the behavior of a CVS server when as "cvs update"
is requested involves building an isomorphic directory hierarchy in
/tmp.  I was pleased to see that a CVS server I had set up had no
problems doing 9 simultaneous "cvs update" runs against /usr/ports.
Absent the -i1024 setting, that would likely have been
less-than-satisfactory.)

Peace,
david
-- 
David H. Wolfskill				david_at_catwhisker.org
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