NFS Test Results

NFS test results

Server Configuration:

Four dual-core, 3 GHz, Intel Xeon processors
8 GB RAM
Four 73 GB, 15K RPM, SAS drives striped using hardware RAID 0
Kernel is 2.6.18.

Client Configuration:

Two dual-core, 3 GHz, Intel Xeon processors
6 GB RAM (tuned down to 4 GB, although /proc/meminfo reports just under 3GB)
Kernel is 2.6.32-rc7
Tuned as follows:

sunrpc.tcp_slot_table_entries=128
/proc/sys/vm/dirty_ratio=76
/proc/sys/vm/dirty_background_ratio=38
With the patch, additional tuning as follows:

/proc/sys/vm/dirty_writeback_centisecs=0
fs.nfs.nfs_max_woutstanding=16

iozone results (client connected to server via 1Gb Ethernet)

linux-2.6.32-rc7 base: run1 run2 run3 merged results (low,high)
linux-2.6.32-rc7 with eager write-back changes: run1 run2 run3 merged results (low,high)
diff of merged results

iozone results (client connected to server via 10Gb Ethernet)

linux-2.6.32-rc7 base: run1 run2 run3 merged results (low,high)
linux-2.6.32-rc7 with eager write-back changes: run1 run2 run3 merged results (low,high)
diff of merged results