NFS Performance Tuning for HP-UX 11.0 and 11i Systems

nfs performance tuning for hp-ux 11.0 and 11i systems page 106

Notes:

Page 106July 22, 2002

buffer cache

considerations

• What is buffer cache and

why do you want to use it?

• Why not just use lots of

memory for buffer cache?

• Static Allocation vs.

Dynamic Allocation

• Server’s interaction with the

syncer(1M) daemon

• How much memory should

you use for buffer cache?

• Measuring Utilization

Sizing buffer cache correctly on NFS clients and servers can be a time consuming

endeavor, but one that can dramatically affect both NFS and overall system

performance. To understand the intricacies and factors involved in correctly sizing

buffer cache, some understanding of what buffer cache memory is, how it is

managed, and how it is searched is needed.

This section describes what buffer cache memory is and why it is so important to

NFS performance. The differences between static and dynamic buffer cache

allocation methods are explained, along with the reasons for selecting one method

over the other. The NFS server’s interaction with the syncer(1M) daemon is

explained, followed by recommendations for determining the appropriate amount

of buffer cache memory to use on a given NFS client or server. Finally, this section

describes the tools available for measuring buffer cache utilization.