if you search under /var directory, of course you see strange directory which named “preserve”.
this directory contains preserved data from interrupted edit sessions. which means, if you open file to edit it using vi command or any editor, the system take a copy from the opened file and keep it under “/var/preserve”, and if your sessions is crashed for any reason, you can reopen the file again using the following steps:
1- run #vi -r to know the preserved files.
2- run #vi -r filename to repoen it again.
Reference:
http://www.tek-tips.com/viewthread.cfm?qid=866619
http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.baseadmn/doc/baseadmndita/fs_var.htm
http://pic.dhe.ibm.com/infocenter/aix/v6r1/index.jsp?topic=%2Fcom.ibm.aix.baseadmn%2Fdoc%2Fbaseadmndita%2Ffsvarover.htm