Logfiles on solaris can be found under var, specifically /var/adm
The messages file should also be contained within that directory
root@solaris:/var/adm# pwd /var/adm root@solaris:/var/adm# cat messages Apr 11 10:28:13 solaris pseudo: [ID 129642 kern.info] pseudo-device: bpf0 Apr 11 10:28:13 solaris genunix: [ID 936769 kern.info] bpf0 is /pseudo/bpf@0
Logrotate will rotate the message file by default.
Other logs can be in /var/adm/log