Manage wtmp Log Size In Aix

1. CONVERT WTMP FILE TO A  TEXT FILE AND REMOVE UNWANTED ENTRIES

WE CAN USE MOST OF THE LOG FILES TO COMPRESS WITH THE SAME PROCEDURE

/usr/sbin/acct/fwtmp </var/adm/wtmp >/tmp/wtmp.out

Trim  wtmp.out

for example to calculate number of lines

# cat /tmp/wtmp.out|wc -l

    914

To trim only last 300 lines

tail -300 /tmp/wtmp.out >> /tmp/wtmp1.out

2. CONVERT THE TEXT FILE TO WTMP FORMAT AND COPY TO THE DEFAULT LOCATION

/usr/sbin/acct/fwtmp -ic <wtmp1.out >/var/adm/wtmp

3. REMOVE UNWANTED FILES

rm /tmp/wtmp1.out

rm /tmp/wtmp.out

4. WE CAN COMPRESS WTMP LOG 

cp /var/adm/wtmp /tmp

compress /tmp/wtmp

or gzip -9 /tmp/wtmp

cp /tmp/wtmp.Z /var/adm/

cp /dev/null /var/adm/wtmp