Files in /var/log

Question

I was looking through my /var/log directory on my PB G4 running OS X 10.4.4 recently and noticed several compressed files. I have a few questions:
1. How come there are so many compressed files?
2. Is it safe to delete them, and how can I delete them?
3. Is there a way to prevent so many from building up in this directory?
daily.out lpr.log.0.gz secure.log.0.gz
fax lpr.log.1.gz secure.log.1.gz
ftp.log lpr.log.2.gz secure.log.2.gz
ftp.log.0.gz lpr.log.3.gz secure.log.3.gz
ftp.log.1.gz lpr.log.4.gz secure.log.4.gz
ftp.log.2.gz mail.log system.log
ftp.log.3.gz mail.log.0.gz system.log.0.gz
ftp.log.4.gz mail.log.1.gz system.log.1.gz
httpd mail.log.2.gz system.log.2.gz
install.log mail.log.3.gz system.log.3.gz
install.log.0.gz mail.log.4.gz system.log.4.gz
install.log.1.gz monthly.out system.log.5.gz
install.log.2.gz netinfo.log system.log.6.gz
install.log.3.gz netinfo.log.0.gz system.log.7.gz
install.log.4.gz netinfo.log.1.gz weekly.out
ipfw.log netinfo.log.2.gz windowserver.log
ipfw.log.0.gz netinfo.log.3.gz windowserver_last.log
ipfw.log.1.gz netinfo.log.4.gz wtmp
ipfw.log.2.gz ppp wtmp.0.gz
ipfw.log.3.gz ppp.log wtmp.1.gz
ipfw.log.4.gz ppp.log.0.gz wtmp.2.gz
lastlog ppp.log.1.gz wtmp.3.gz
lookupd.log.0.gz ppp.log.2.gz wtmp.4.gz
Thanks,
Mike

Answer 1

Hi Mike,
   There is no need to worry about their growing. In fact, that's why they are there. They are the results of log rotation by the periodic scripts. Notice that many logs start with the same name, such as ftp.log, ftp.log.1.gz, ftp.log.2.gz, ftp.log3.gz, and ftp.log.4.gz. When you first installed the OS, there was only one, ftp.log. The next time the 500.weekly script runs, it appends a one, '1', to the filename, gzips the file and creates a new ftp.log. A week later, the next time the 500.weekly script runs, it moves ftp.log.1.gz to ftp.log.2.gz, appends a 1 to the new ftp.log, gzips the file and creates a new ftp.log. This process repeats until the ftp.log.4.gz file is created. A week after that, the ftp.log.4.gz is deleted and the former ftp.log.3.gz takes it place.
   Thus, every week each file's number increases until it's 4 weeks old and then it's deleted. The total number of files doesn't increase and, modulo variations in activity, the total size of the collection remains roughly constant. Older records are kept in as compact a form as possible and really old records are removed to make way for new ones.
   Therefore, your goal of limiting the size of the log files is implemented for you in a more efficient manner than you might have imagined. However, since you don't use the old ones, you could delete them if you're really hard up for space. Oh, one more thing -- more active log files, like system.log, are rotated daily and a week's worth of them are maintained.
Gary
~~~~
   A successful [software] tool is one that was used to
   do something undreamed of by its author.
         -- S. C. Johnson