Date: Fri, 30 Jan 1998 22:14:02 -0500 (EST) From: "John W. DeBoskey" <jwd@unx.sas.com> To: freebsd-current@FreeBSD.ORG Cc: jwd@unx.sas.com (John W. DeBoskey) Subject: NFS v3 3.0-Current performance questions Message-ID: <199801310314.AA16700@iluvatar.unx.sas.com>
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Hello,
I have a series of NFS v3 performance related questions which I
would like to present.
The setup: 6 266Mhz PII 128Meg computers hooked up to a
network appliance file server via NFS V3.
Running 3.0-980128-SNAP.
Problem: This system is running a distributed make process
which accesses (minimum) 2564 h files in 20+ directories
located on the file server.
I would like to buffer as much of (if not all) the
directory information concerning these files and the
file contents.
Questions:
Is it possible to tune the amount of cached directory information
in the NFS v3 protocol?
Is is possible to tune the amount of file datablock contents which
are cached? From nfsstat, note the number of BioR hits and misses
from simply running a job which continuously cats the files (of
course I may be mis-interpreting the output).
Cache Info:
Attr Hits Misses Lkup Hits Misses BioR Hits Misses BioW Hits Misses
69997 9172 43654 8700 10006 12674 0 0
fyi: The time to cat all the files to /dev/null : 3 iterations :
6.78s real 0.05s user 1.42s system
6.82s real 0.03s user 1.41s system
6.78s real 0.01s user 1.46s system
( I'd like to cut this by at least 50% :-)
Using the default (NBUF=0) value causes nbuf to aquire the
value 3078 for each system by default. I have set NBUF=8196 with
no real performance gain, so I don't think this is the right
direction. Comments? I beleive I can get a big gain if I can simply
reduce the number of BioR Misses. Again, Comments?
From a performance testing standpoint, it would be nice if we could
add a 'clear the counters' option to nfsstat so that root could reset
the stat numbers to zero. Comments?
I do not beleive I need to add memory to these boxes either. Note the
number of free vm pages in the following vmstat output.
$ vmstat -s
127855 cpu context switches
877149 device interrupts
52881 software interrupts
11625 traps
91484 system calls
0 swap pager pageins
0 swap pager pages paged in
0 swap pager pageouts
0 swap pager pages paged out
243 vnode pager pageins
1165 vnode pager pages paged in
0 vnode pager pageouts
0 vnode pager pages paged out
0 page daemon wakeups
0 pages examined by the page daemon
0 pages reactivated
4287 copy-on-write faults
3173 zero fill pages zeroed
5 intransit blocking page faults
12564 total VM faults taken
20366 pages freed
0 pages freed by daemon
5237 pages freed by exiting processes
296 pages active
1657 pages inactive
1243 pages in VM cache
3427 pages wired down
25252 pages free
4096 bytes per page
79741 total name lookups
cache hits (81% pos + 0% neg) system 0% per-directory
deletions 0%, falsehits 0%, toolong 0%
$
Any and all comments are welcome.
Thanks,
John
--
jwd@unx.sas.com (w) John W. De Boskey (919) 677-8000 x6915
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