Date: Mon, 23 Jul 2001 17:03:25 -0400 From: "Brad L. Chisholm" <blc@bsdwins.com> To: freebsd-questions@freebsd.org Subject: Inconsistent NFS write performance Message-ID: <20010723170325.A29362@bsdone.bsdwins.com>
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Hi,
I have two systems with different hardware, but nearly identical FreeBSD
setups. One of the systems is experiencing extremely poor NFS write
performance, although other network and filesystem performance (FTP and
RCP of large files, bonnie tests, etc) is similar to the other system.
I cannot find the source of the poor NFS write performance for this system,
and it's frustrating because this is the system we want to put in place
as an NFS fileserver.
Does anyone have suggestions?
Here are some details:
- Both systems are running the same snap of 4.3-STABLE, and are
using the same kernel (copied to both systems).
- Both systems are plugged into the same switch, and are mounted on the
same client which is also plugged in to the same switch.
- System 1 (the bad one), is a Dell PowerEdge 2550, dual processor 933Mz P3
with 512Mb memory and an Ultra 160 SCSI drive, Intel 10/100 (fxp) ethernet
adapter [Not running an SMP kernel]
- System 2 is a Dell Optiplex 150, single processor 866 P3 with 256Mb mem
and an ATA100 drive, Intel 10/100 (fxp) ethernet adapter.
- ftp and rcp, both from and to, show similar performance on both systems,
near the 100Mbs network limit.
- NFS read performance for System 1 is slightly worse than System 2, but
NFS write performace is 6-8 TIMES WORSE! See details below.
======================== System 1 (BAD NFS write performance) =========
FreeBSD server1.bsdwins.com 4.3-STABLE-20010625 FreeBSD 4.3-STABLE-20010625 #0: Mon Jun 25 21:43:20 GMT 2001 root@tribble.bsdwins.com:/usr/src/sys/compile/GENERIC i386
Copy of a large (572MB) file via NFS *from* this system:
client# /usr/bin/time cp /server1/tstfile /tmp
59.43 real 0.03 user 8.35 sys
server1# nfsstat -sW -w1
GtAttr Lookup Rdlink Read Write Rename Access Rddir
0 0 0 1140 0 0 0 0
0 0 0 1158 0 0 0 0
0 0 0 1180 0 0 0 0
0 0 0 1138 0 0 0 0
0 0 0 1170 0 0 0 0
Copy the same file via NFS back *to* this system:
client# /usr/bin/time cp /tmp/tstfile /server1/zztest
428.09 real 0.03 user 8.62 sys
server1# nfsstat -sW -w1
GtAttr Lookup Rdlink Read Write Rename Access Rddir
0 0 0 0 217 0 0 0
0 0 0 0 236 0 0 0
0 0 0 0 83 0 0 0
0 0 0 0 247 0 0 0
0 0 0 0 89 0 0 0
0 0 0 0 554 0 0 0
0 0 0 0 71 0 0 0
======================== System 2 (Good NFS write performance) =========
FreeBSD server2.bsdwins.com 4.3-STABLE-20010625 FreeBSD 4.3-STABLE-20010625 #0: Mon Jun 25 21:43:20 GMT 2001 root@tribble.bsdwins.com:/usr/src/sys/compile/GENERIC i386
Copy of a large (572MB) file via NFS *from* this system:
client# /usr/bin/time cp /server2/tstfile /tmp
55.72 real 0.03 user 8.58 sys
bb01t06# nfsstat -sW -w1
GtAttr Lookup Rdlink Read Write Rename Access Rddir
0 0 0 1266 0 0 0 0
0 0 0 1256 0 0 0 0
0 0 0 1283 0 0 0 0
0 0 0 1255 0 0 0 0
0 0 0 1281 0 0 0 0
Copy the same file via NFS back *to* this system:
client# /usr/bin/time cp /tmp/tstfile /server1/zztest
51.31 real 0.01 user 9.55 sys
server2# nfsstat -sW -w1
GtAttr Lookup Rdlink Read Write Rename Access Rddir
0 0 0 0 1449 0 0 0
0 0 0 0 1438 0 0 0
0 0 0 0 1400 0 0 0
0 0 0 0 1405 0 0 0
0 0 0 0 1426 0 0 0
0 0 0 0 1366 0 0 0
A copy of this email, and dmesg output from each machine can be found
at http://www.bsdwins.com/~blc/nfsprob1.html.
Please let me know if you have any ideas. This one has me baffled.
Thanks,
-Brad
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