Messages in this thread | | | Subject | Re: NFS read performance ugliness | From | Zlatko Calusic <> | Date | 03 Nov 1998 10:50:01 +0100 |
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smurf@noris.de (Matthias Urlichs) writes:
> I was performance-testing the kernel and userspace NFS implementations > yesterday, to see if we have any chances to outperform an NetApp server. > > As of 2.1.127-pre3 (with the NFS patches from the latest knfsd package), > we do NOT. > > The main problem is horrible read performance across NFS, which seems to be > related to the server not doing its job WRT reading ahead from disk. > > I verified this by doing a few tests with bonnie: > > -------Sequential Output-------- ---Sequential Input-- --Random-- > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU > Barrac. 350 4333 88.7 6622 12.2 2394 8.5 4154 83.6 5275 6.8 92.0 1.7 > +DCAS-W 250 4304 88.2 6634 12.1 2692 9.7 3052 61.5 5750 7.4 122.7 2.1 > +2SCSI 350 4344 89.1 8757 16.1 3534 12.9 3309 66.6 7784 11.1 101.7 2.0 > NetApp 1000 2019 41.5 2243 3.8 1522 3.8 2691 57.0 4723 7.9 95.6 2.8 > nfs 350 2047 41.8 5445 10.5 1516 4.1 976 20.3 1017 1.8 31.0 1.2 > knfs 350 2421 49.1 4639 11.0 1799 5.1 970 20.4 1027 1.9 32.2 1.2 > 80 2464 49.1 4132 11.2 1655 4.8 1459 30.2 1741 3.3 453.6 9.6 > 70 3057 63.0 4340 12.2 1713 4.3 1848 38.0 3582 6.7 969.6 30.3 > 60 3522 74.4 4184 8.0 2064 5.4 2536 51.3 4946 4.4 376.6 4.4 > 50 2574 52.0 2447 8.1 5735 21.1 4697 91. 187292 98. 4067.4 26.5 >
Well, you should be quite happy, cause I'm seeing very abysmal performance here. Much lower numbers than yours, when using Sun Ultra2 as server (2 x 168 MHz, 128 MB RAM, Solaris 2.6) and P166MMX (166 MHz, 64 MB RAM, Linux 2.1.125) as client.
-------Sequential Output-------- ---Sequential Input-- --Random-- -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU 30 72 1.2 86 0.9 82 0.6 948 15.0 1050 6.9 68.6 2.6
Writes are so slow that NFS is practically unusable. Too bad, cause I have lots of unused disk space on Suns, around here.
> > NB: Obviously, all tests were run with 100-mbit Ethernet cards (tulip > driver) and a 100-Mbit switch, full duplex. >
My tests are on very similar equipment, both computers on 100MBps full-duplex ports on switch. DE500-BA (de4x5 driver) on Linux.
I tried changing rsize/wsize parameters, but achieved nothing.
All other types of network communication run at half to full network speed (50 - 100MBps). Also when mounting Sun's disks to other Sun, performance is quite OK.
Is there any workaround?
-- Posted by Zlatko Calusic E-mail: <Zlatko.Calusic@CARNet.hr> --------------------------------------------------------------------- Man has his will. Woman has her won't!
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