File systems

Local (JFS/JFS2) filesystems

/ (root), /var and /tmp should be at least 64MB (131072 512-byte blocks) in size for AIX <=5.1, and 128MB, 512MB and 512MB, respectively, for AIX >=5.2. The amount of necessary paging space depends on the nature of the applications. The installation default may suffice, but for memory hogs one should consider paging space about as large as the machine's RAM.
The /tmp filesystem should be cleaned on a daily basis, edit /var/spool/cron/crontabs/root or use
   crontab -e
to insert
   0 3 * * * /usr/sbin/skulker >/dev/null # obsolete
   0 3 * * * /opt/bin/scavenger -t+1 /tmp >/dev/null
which will cleanup at 3 AM.


This filesystem usually holds optional software, mostly freeware. It is created automatically during installation of AIX>=5.1. On earlier versions one has to create it manually on rootvg with a size of 64MB, better 128MB:
   smitty storage: Logical Volumes - Add a Logical Volume 
   smitty storage: Filesystems - Add / Change / Show / Delete File Systems
   smitty storage: Filesystems - Add / Change / Show / Delete File Systems
   smitty storage: Filesystems - Mount a File System
or per command line
   mklv -y'hd10opt' -t'jfs' rootvg 1               # 1 partition to start with
   crfs -v jfs -d'hd10opt' -m'/opt' -p'rw' -A yes  # filesystem with default parameters
   chfs -a size='262144' /opt                      # increase it to 128MB      
   mount /dev/hd10opt /opt                         # mount it

Remote filesystems, mounted via automounter

There are user, scratch and data filesystems, as well as freeware and commercial applications.
  1. Prepare links and directories,
       rm /u     # it's only a softlink to /home 
       mkdir /u
  2. Prepare the automounter files (the comments in the following should be omitted, their content belongs into the respective /etc/auto.* file)

  3. At GSI, for a new machine, the operating group ( has to be informed to regularly update the autofs (file /etc/auto.u) maps on this machine.

Last update: 8-May-2013, M.Kraemer

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