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Generic Installation Considerations

Generic Installation Considerations

• Overview of Unix system file structure

• Placing cluster components

System File Structure

• The root or / directory is located at the top of a hierarchical tree. The organisation of the file system has certain supplier specific elements but follows a generic pattern. The components of root which are of interest are:
  • bin

  • etc

  • lib

  • tmp

  • usr

  • var

/ File Structure

• bin - essential programs in executable form usually a link to usr/bin

• etc - various system administration files, a package will sometimes place or modify files in etc. Also files such as rc.local or files in rc2.d (SVR4) need to be modified to start applications at boot time.

• lib - essential system libraries, this is usually a link to usr/lib

• tmp - temporary files cleared when the system is booted, used by applications lock or scratch files (pvm daemon in old versions). A potential problem area and a separate disk or disk partition should be considered. Alternate - /usr/tmp.

• usr - user file system (a historic name as most of the Unix system files now reside here). Every supplier has a different usr structure but the essentials given here are common (mostly).
  • adm - linked to ../var/adm

  • include - header files used in C programs

  • local - local/lib and local/bin commonly used for 3rd party products

  • man - link to share/man

  • share - files which may be shared across machines (only put man pages here)
    • man - manual pages: man/man.1 - user commands....; man/man.l local commands; man/man.n new commands

• home - individual user's files should be placed on a different disk (partition) via a link in usr (eg. /usr/people -> /people) or under a directory such as /home (SUN).

• var - system files which a liable to grow. Place these on a separate disk (partition). For example:
  • adm - accounting

  • spool - printing, email, cron

  • tmp - alternative to /usr/tmp

Component Placement

• By default packages are installed in the usr hierarchy: executables in usr/bin and libraries in usr/lib (or usr/local). This can fill the usr disk with disastrous consequences.

• If software packages offer a mechanism for installation in a user-defined directory, create a (large) separate area for as much 3rd party software as possible.

• Some products offer system specific installation tools such as inst (Silicon Graphics). This simplifies installation (and removal) but at a price:
  • share usr across machines - performance penalty

  • install on each machine - disk space penalty and repetition of effort