using cron to backup logs in unusual circumstances

ShadowWizard · 04-28-2012, 09:27 PM

I don't know much about linux to be honest, I am just learning because I have a server running on one. What i am doing is looking for a way to automatically backup the log files, compress them, and put them somewhere else. Here is the thing, the server creates a new log file every time it is restarted with the date and time of the restart in the file name. So if it is not restarted for days, the log file will indicate a day several days ago, because that is when it was originally created. Next problem, if that log file disappears, the server doesn't create another one, it just stops logging.
So, basically I need to find a way to make a command for Cron to "Backup and delete all but the most recent log file." And I have no idea where to begin.
Just to clarify in case I am not totally clear. We will say today's date is well, today. 4-28. I have the following log files:
4-18.log
4-22.log
4-23.log
4-27.log
I need to backup and delete 4-18, 4-22, and 4-23. But I need to leave 4-27 alone.
Now, keep in mind that the most recent log file is not necessarily for yesterday. In the above example 4-23.log contains information from the 23rd, 24th, 25th, 26th and part of the 27th. The only reason 4-27 was created was because the server was restarted on the 27th, and thus because today is the 28th 4-27 will contain log information frm the rest of the 27th and the 28th.
I was thinking (if it is even possible) to create a cron entry that will do this for files that had there last access date yesterday. But again, I have NO idea how to do any of this.

Thanks in advance.

em31amit · 04-28-2012, 09:42 PM

I am thinking that you need to create a shell script than include it to in crontab.

ShadowWizard · 04-28-2012, 09:43 PM

And I wold have NO idea how to do that.

em31amit · 04-28-2012, 09:51 PM

read bash scripting on google/other website. I will try to create it later on.

em31amit · 04-30-2012, 07:30 AM

here is one script, i have created for you. You need to change some variables values accordingly to your need

this script will backup and delete file except last reboot date file.

try this, I am pretty much sure that it will work.

Quote:

#!/bin/bash

# Created By : Amit M.
# em31amit

#Last Reboot date
RDATE=4-28

BackupName="backup-`date +%s`.tgz"

#Backup Directory Location
BackupDir=/var

#Log Files location
LogDir=/var/tmp

echo " Changing Directory to $LogDir"

cd $LogDir

echo " Taking backup to All Log file to $BackupDir Directory"

/bin/tar -czvf $BackupDir/$BackupName *.log --exclude=$RDATE.log

echo " Deleting files all except $RDATE.log (Latest Preserving scheme)"

find $LogDir -type f $ -iname "*.log" ! -iname "$RDATE.log" $ -print -exec rm -rf {} \;

echo " All Done "

echo " Backup file name is $BackupDir/$BackupName "

If you found this information is usefull and working than please mark is yes and solved.