Using the linux commands below you can find files on a system with limited free space. In the below example you will find “/dev/mapper/VolGroup00-LogVol00” has 4% available space.
[root@centos ~]$ df -h Filesystem Size Used Avail Use% /dev/mapper/VolGroup00-LogVol00 14G 13G 548M 96%
The “VolGroup00-LogVol00” is a directory mapped as a volume used for logging. If you do not know where the logs are you can use the below command to find the large directories. You can also use a larger depth setting but the output will quickly become too much to show on the screen. As you can see below the /usr directory is 11 GB in size.
[root@centos ~]$ du -h --max-depth=1 8.0K ./mnt 541M ./lib 8.0K ./srv 52M ./etc 36M ./sbin 35M ./boot 84K ./tmp 7.9M./bin 26M ./tftpboot 0 ./proc 0 ./sys 68K ./home 0 ./misc 5.9M./opt 11G ./usr 8.0K./selinux 0 ./net 241M ./var 8.0K ./media 28M ./lib64 76K ./dev 12G .
The space consumed is very often log files used by a service. In this example a service created one log file per day and no cron jobs were setup to clear the logs. Once it is determined where the logs are located use the below command to clear out logs files older than 100 days where part of the log names began with the word “server”.
[root@centos ~]$ find /usr/local/service/logs/server* -mtime +100 -exec rm {} ;
If you find there is one long contiguous log instead of many individual logs you can truncate it. First rename the log file.
[root@centos ~]$ mv service.log service.log.old
Now, copy the last 100 lines of the log to a new log file.
[root@centos ~]$ tail -n 100 service.log.old > services.log
If you find the log was fed from the head instead of the tail you would copy the first 100 lines instead of the last 100 using the command below.
[root@centos ~]$ head -n 100 service.log.old > services.log
Next review the new log to ensure the events are recent.
[root@centos ~]$ cat service.log | less
If it looks good remove the old log.
[root@centos ~]$ rm services.log.old
Finally confirm free space has been recovered using the below command once more.
[root@centos ~]$ df -h Filesystem Size Used Avail Use% /dev/mapper/VolGroup00-LogVol00 14G 6.06G 7.06G 47%
