On some systems the IFS may be a very significant portion of your system. The first tool to start with in determining if it is a significant portion of your IBM i is to run the pair of commands RTVDSKINF and PRTDSKINF. A sample result may show you something like the following:
Description Disk 1,000,000 bytes User libraries 61.45 4810922.84 User directories 1.15 90209.35 Folders and documents .00 .94 QSYS .08 6211.86 Other IBM libraries .55 42719.19 Licensed Internal Code .55 42878.36 Temporary space 4.83 378368.34 Unused space 31.10 2435026.19 System internal objects .26 20288.37 Objects not in a library .00 .02 QTEMP libraries .00 311.18 TOTAL 99.97 7826936.64
The portion of that which is IFS is the portion called "User directories". On this system it is only 1.15%. I have seem some systems like the following:
% of Size in Description Disk 1,000,000 bytes User libraries .07 16375.86 User directories 71.76 16703615.24 …
The commands RTVDSKINF and PRTDSKINF really do not drill down into the IFS. For that you need the pair of commands RTVDIRINF and PRTDIRINF. Some people do not like the output of PRTDIRINF. An alternative to PRTDIRINF is to work directly with the files generated by RTVDIRINF. See Working with output of the RTVDIRINF and PRTDIRINF commands
IBM i Access - Client Solutions has a tool in it called Run SQL Scripts. Run SQL Scripts comes with some templates for analyzing the output of RTVDIRINF. One is "Analyze IFS storage consumption".
Here are some areas of the Integrated File System (IFS) you may wish to clean up on a periodic basis
The directory /QFPNWSSTG is often the largest directory on some systems. These systems are often in one of two catagories. One is a system which hosts disk for other systems. For example, you may have an lpar of IBM i hosting disk for LPARs of IBM i and/or AIX or LINUX on the same Power Server. The other category may be a carry over from older versions of IBM i as the current versions no longer support hosting x86 family of cards directly in a Power server. These cards had many names such as FSIOP, IPCS, IXS and so on. You should not try to delete data within QFPNWSSTG directly but instead you should use the command WRKNWSSTG. See also WRKNWSD. Know your system first and determine if you are hosting other systems before proceeding to delete this kind of data.
The QTOT* files in this NTP directory are the log files for your NTP or Network Time Protocol server running on IBM i. You can delete these QTOT* files at will. To turn off logging see the command CHGNTPA ACTLOG(*NONE) SVRACTLOG(*NONE).