Hub/Switch Installation Guide

Chapter 2 HPSS Planning
134 September 2002 HPSS Installation Guide
Release 4.5, Revision 2
2.10.3.2.8 Disk Space Requirements for Running NFS Daemon
The HPSS NFS server memory and disk space requirements are largely determined by the
configuration of the NFS request processing, attribute cache, and data cache. Data cache memory
requirementscanbe estimatedby multiplyingthedata cachebuffersize bythe numberofmemory
data cache buffers.
Attribute cache memory requirements can be estimated by combining requirements for directory
name with fileattribute memory requirements. The total numberof name space objects kept inthe
NFS attribute cache is determined by the maximum number of entries in the attribute cache least
recently used (LRU) list. A portion of these entries will be directories, and the rest will be bitfiles,
symbolic links, or hard links.
Directory name memory requirements are determined by multiplying the estimated number of
cached directoriesby thedirectorysizeconfiguration. Estimatingthe numberof cacheddirectories
can bedone by multiplyingthe number ofentries in theattribute cache LRUlist by thepercentage
of directories to files at the site. For example, if the LRU list maximum is set to 100 and the
percentage of directories at the site is 1 directory to 10 files (10%), the estimated number of cached
directories is 10.
File attribute memory requirements are determined by subtracting the number of cached
directoriesfrom the maximum numberof entrieson theLRU list and multiplying the resultby100.
Request processing memory requirements can be estimated by multiplying the number of ONC
remote procedure call threads by 65 KB.
The HPSS NFS Server requires disk storage for five UNIX files:
• Exports file—a text file that specifies how NFS access is offered.
• Remote mount (rmtab) file—this file, in the same directory as the exports file, is a text file
that identifies what clients have mounted HPSS directories.
• Credentials map file—a text file that is used to checkpoint the NFS credentials map. The
credentials map file size will be based on the number of entries in the credentials map
cache.
• Checkpoint file—required by the data cache. The data cache checkpoint file size is related
to the number of cache entries, but is much smaller than the cache entry file.
• Entry file—required by the data cache. Disk storage for the data cache entry file is
determined by multiplying the number of cache entries by the data cache buffer size. The
data cache entry file should be placed in its own disk partition to avoid disk contention.
2.10.3.2.9 Disk Space Requirements for Running SSM
IfSSMisconfiguredtobufferalarmandeventmessagesinadiskfile,eachSSMDataServerprocess
will require an alarm file approximately 5MB in size. This file may be placed wherever it is
convenient. There is normally only one Data Server process.