Date: Fri, 20 Aug 1999 15:06:53 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Steve Ames <steve@cioe.com> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Async NFS exports? Message-ID: <199908202206.PAA65547@apollo.backplane.com> References: <199908201813.NAA66892@ns1.cioe.com>
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: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 <dillon@backplane.com> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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