On 2013-01-30, Constantine A. Murenin muren...@gmail.com wrote:
Hello misc@,
On OpenBSD 5.2 amd64, I'm storing 1.4GB of source code files and about
8x 150MB indices on an mfs partition, plus a gig or two of other
automatically-generated files.
If I run mount_mfs to load all this stuff from a regular drive, then
the amount of memory used by mount_mfs(8) is about the same as the
amount of Used disc space as reported by df(1).
However, if I re-run index generation on an mfs, then after it's all
done, memory usage by mount_mfs(8) noticeably exceeds Used disc space.
As a workaround, I found that it's possible to copy all the files
over to a new mount_mfs(8) process, after the indices have been
re-generated, and the new process will at first have a much better
memory usage, but this seems a little inconvenient and would also
require a temporary burst of extra RAM to accomplish.
Should I worry that on a 6GB partition that is only 4GB full,
mount_mfs uses 5GB of memory after about 3GB of data gets mingled? Is
mount_mfs swappable? If I end up being short on memory, would that
extra 1GB from mount_mfs(8) be swapped out without affecting the
performance? Or is there a way to run some kind of garbage collector
or otherwise improve on an mfs memory use?
% df -hi | fgrep -e Used -e mfs ; mount | fgrep mfs ; ps aux | fgrep
-e USER -e mfs
Filesystem SizeUsed Avail Capacity iused ifree %iused Mounted on
mfs:18610 5.9G4.1G1.5G73% 439864 35770255% /grok/mfs
mfs:18610 on /grok/mfs type mfs (asynchronous, local, nodev, nosuid,
size=12582912 512-blocks)
USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND
root 18610 0.0 40.2 6291936 5048352 ?? IsSun07PM0:22.56
/sbin/mount_mfs -o rw -s6G -f2048
Cheers,
Constantine.
This is expected with mfs, don't set the filesystem to be larger
than the amount of memory you would like it to use.
I don't know how it behaves with swapping.
