:I asked this on stable but didn't get a response... Would I get any
:performance increases by mounting NFS exported partition as Async?
:
:Would my soul be tormented in purgatory for doing it?
:
:Just to be clear... I am wondering if mounting (on the NFS _server_) a
:partition (that is exportable) as async will have any performance
:benefits to the NFS clients?
:
:-Steve
Ok, I've run some more tests. Basically you want to run NFSv3 under
CURRENT and you want to run at least 3 nfsiod's. On a 100BaseTX network
this will give you unsaturated write performance in the ballpark of
9 MBytes/sec. Saturated write performance, that is where you write more
then the client-side buffer cache can handle, will stabilize at
2.5 MBytes/sec. I have a patch for CURRENT which will increase the
saturated write performance to 4.5 MBytes/sec (basically by moving the
nfs_commit() from nfs_writebp() to nfs_doio() so it can be asynchronized).
Hopefully that patch will go in soon but there's a pretty big backlog of
patches that haven't gone in yet, some over a week and a half old, so...
In anycase, even without the patch if you run a couple of nfsiod's and
do not saturated the buffer cache you should get optimal performance.
Backing-porting the patch for nfs_commit to STABLE is possible but is
not likely to help much because the major performance restriction in
STABLE is related to buffer cache management, not NFS.
OS #nfsiod's unsaturated saturated
write perf. write perf.
( ..... 100BASETX ...... )
CURRENT 0 9 MBytes/sec 2.5 MBytes/sec
CURRENT 4 9 MBytes/sec 4.5 MBytes/sec(w/patch)
STABLE 0 3 MBytes/sec 3 MBytes/sec(1)
STABLE 4 4 MBytes/sec 3 MBytes/sec(1)
note(1): saturated performance under STABLE is extremely inconsistant
-Matt
Matthew Dillon
<dil...@backplane.com>
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