User guide

Configuring NFS servers 5–3
5.1.2 Configuration factors for NFS servers
When configuring HP SFS client nodes as NFS servers, consider the following points:
• A Lustre file system may be exported over NFS or over Samba, but may not be exported over both
NFS and Samba at the same time.
• Multiple HP SFS client nodes configured as NFS servers may export different Lustre file systems.
• Multiple HP SFS client nodes configured as NFS servers may export the same Lustre file system.
• The NFS server must be an HP SFS client node that only provides NFS server services. Do not run
applications or other services on the NFS server.
• Only use an HP SFS enabled NFS server for NFS exports; using other Lustre clients may result in data
coherency problems.
• Ensure that the NFS server and the HP SFS servers have synchronized clocks using Network Time
protocol (NTP).
• When stopping a Lustre file system that has been exported over NFS, you must first stop the NFS
server before you stop the Lustre file system.
• The NFS server must be running a Linux 2.4 based kernel with the HP SFS client software installed.
Using a Linux 2.6.x kernel on the NFS server is not supported in this release.
• If the NFS server is configured to access the Lustre file system via an InfiniBand interconnect, the
Voltaire InfiniBand Version 3.4.5 interconnect driver must be used, because it is compatible with Linux
2.4.x kernels.
• The NFS server must have the following ports open for the services to work correctly:
• TCP and UDP: Port 111 (portmapper)
• TCP and UDP: Port 2049 (NFS)
• TCP and UDP Ports: 1024–65535 (dynamic ports allocated by portmapper)
• The lockd daemon must be active on the NFS server and on all NFS client systems accessing the
exported file system. The lockd daemon is a standard NFS component that provides file locking
services to the NFS client systems. NFS file coherency is dependent on proper use of POSIX file
locking when multiple NFS client systems are accessing the same file on an NFS server.
• If the NFS server will serve HP-UX NFS client systems, and you want file locking to work, add
insecure to the entries in the /etc/exports file on the NFS server.
For example, if the current parameters are as follows:
/mnt/scratch *(rw,sync,no_root_squash)
Add insecure so that the parameters are as follows:
/mnt/scratch *(rw,sync,no_root_squash,insecure)
• HP recommends that you create multiple swap areas (of the same priority) if you have multiple devices
on independent channels. This allows the kernel to swap in parallel. Also, HP recommends that you
keep swap areas on less-used devices/channels, so that heavy non-swap I/O is not hindered by
swap I/O.