Mount Parameters Combinations

Tuning the mount parameter combination of rpcTimeOut, MaxOutstandingPackets, readSize and writeSize based on the network load, UNIX machines, and, the hardware gives a significant increase in NFS Gateway performance.

You can vary the combination of mount parameters based on your network resources:

• Optimal Network: Retain the default values of rpcTimeout, maxOutstandingPackets, readSize, and writeSize parameters.

• Highly Used Network/Slow UNIX machine: Increase the values of the rpcTimeout parameter and decrease the values of maxOutstandingPackets, readSize, and writeSize parameters.

For example, consider the following network setup:

• UNIX OS Solaris* 8.0 installed
• UNIX machine with the following attributes:
  • Solaris 8.0
  • Compaq* ProLiant* 7000, P II, Xeon at 450 Mhz, RAM = 1GHz

• NetWare^® machine:
  • Compaq ProLiant 7000, P II, Xeon at 450 Mhz, RAM = 1GHz
  • NetWare 6 Pack Support Pack 3 with Nw6nss3c.exe installed.

• NetGear HUB 100 MBPS
• NFS Version 3
• Windows workstation with following attributes:
  • Dell* Optiplex* GX240, P4, 512 MB RAM
  • Windows XP
  • Novell Client^TM Version 4.90

In this network setup, you can tune the combination of mount parameters in the following ways:

Read Performance

• Change the maxOutstandingPacket parameter value and leave the readSize and writeSize parameter values constant at 32.

  The following table shows the performance time of read operation for a 100 MB file in seconds.

  readSize	writeSize	maxOutstandingPackets	Time in Seconds
  32	32	2147483647	30
  32	32	1	135
  32	32	10	24
  32	32	20	25
  32	32	12	25
  32	32	11	25
  32	32	9	31
  32	32	8	44

• Change the maxOutstandingPacket parameter and leave the readSize constant at 32 KB.

  The following table shows the performance time.

  File Size	maxOutStandingPackets at 10(Time in seconds)	maxOutStandingPackets at 2147483647(Time in seconds)
  500 MB	146	157
  1GB	344	333
  2 GB	653	582

• Change the readSize parameter value, set maxOutstandingPackets set to 10 (the optimal value) and set the writeSize value to 32.

  The following table shows the read operation performance for 100 MB file in seconds:

  readSize	Average Time in Seconds
  32	25
  16	40.5
  8	29
  4	35

Write Performance

• Change the maxOutstandingPackets parameter value and leave readSize and writeSize parameter values constant at 32.

  The following table shows the write operation performance for a 100 MB file in seconds:

  readSize	writeSize	maxOutstandingPackets	Time in Seconds
  32	32	2147483647	25
  32	32	1	37
  32	32	10	25
  32	32	50	25
  32	32	12	28
  32	32	9	28
  32	32	6	30

• Change the maxOutstandingPackets parameter and leave the writeSize parameter value constant at 32 KB.

  File Size	maxOutStandingPackets at 10(Time in seconds)	maxOutStandingPackets at 2147483647(Time in seconds)
  500 MB	118	107
  1GB	236	227

• Change the writeSize parameter value, set maxOutstandingPackets and readSize parameter values constant at 10 (the optimal value) and 32 respectively.

  writeSize	Average Time in Seconds
  32	25
  16	31
  8	28.6
  4	31