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

nfs performance tuning for hp-ux 11.0 and 11i systems page 46

Notes:

Page 46July 22, 2002

nfsd

What happens at nfsd start time?

1. Stream Head Buffer Size Calculated

2. Per-CPU nfsd Pools Created

3. rpcbind(1M) Bindings Established

4. Number of nfsds Increased if Needed

5. Stream Head Replicated per-CPU

6. nfsds Bind to per-CPU Pools

When the nfsds are started, several important things happen:

1. Stream Head Buffer Size Calculated

The size of the stream head buffer is calculated based on the number of nfsds launched. This

buffer size ranges between 64KB and 512KB. The size increases by 8KB for each new nfsd

launched. This means that at least 64 nfsds must be running in order for the kernel to allocate

the maximum allowable buffer space for each stream head (i.e. 64 nfsds * 8KB = 512KB).

2. Per-CPU nfsd Pools Created

A separate pool of nfsds is created for each CPU.

3. rpcbind(1M) Bindings Established

The daemons register support for NFS PV2 and PV3 for both UDP and TCP transport protocols.

4. Number of nfsds Increased if Needed

The kernel allocates an equal number of nfsds to each per-CPU pool.

5. Stream Head Replicated per-CPU

A separate stream head is allocated for each CPU, allowing each CPU to maintain a separate

queue of requests to process.

6. nfsds Bind to per-CPU Pools

The individual nfsd daemons are evenly distributed among the per-CPU pools.