=pod
=head1 NAME
B<savelogs> Frequently Asked Questions
=head1 SYNOPSIS
A collection of frequently asked questions about B<savelogs>.
* THIS DOCUMENT IS NOT COMPLETE NOR DOES IT CONTAIN MUCH VALUE AT ALL.
PLEASE READ THE MAN PAGE FOR SAVELOGS FOR REAL ANSWERS. THIS DOCUMENT
IS CURRENTLY JUST A PLACEHOLDER FOR A FUTURE FAQ *
=head1 DESCRIPTION
Q. I don't understand the process phases (move, archive, etc.). What's
really going on here?
A. read the manual.
Q. Can I archive just one log file on a regular basis?
A. Sure. You have read the man page, right? You need to decide what
"archive" means for you. Some people think archive means to rename
the file and then compress it. Other people think it just means to
rename the file, etc.
Q. How does savelogs behave with very low disk space?
A. Savelogs uses tar to archive log files and gzip to compress them.
If you're adding logs to an archive and then compressing that
archive, you must be able to guarantee this much disk space:
- size of current log * 2
- size of archive uncompressed
If this is more space than you have, consider using the 'period'
option, which will compress a certain quantity (which you specify
with the 'count' option) of individual logs. While this does not
save as much total disk space (tar files compress slightly better
than individual logs because of the added redundancy of multiple
logs in one file), it does reduce the free disk space required to
save the log files because you don't have to decompress the tar
file before adding the log file to it.
You may also add the 'count' option which will limit the number of
logs saved. By also specifying the 'size' option and running
savelogs more frequently, you can get a good idea how much total
disk space you will need for all of your logs.
To calculate how much log space you'll need, you can also set the
'size' limit so that logs only get archived if they are a minimum
size. This way you can know that the log size will be within a
certain range (you can run savelogs several times a day to get
finer control over the log size). Multiply that size plus that log
compressed (roughly 10:1) times the number of logs. For example:
savelogs --size=500 --count=5 --period --conf=/etc/savelogs.conf
will yield:
500K (approx) log
50K log.0.gz
50K log.1.gz
50K log.2.gz
50K log.3.gz
50K log.4.gz
===========================
750K total logs
You now need roughly only 750K for your logs. Then if you limit
your user quotas, you can guarantee you never run out of space
for any reason (barring core dumps and other unforseeable acts).