How to debug if a logical volume is still taking space after deleting all its contents ?

Scenario. I deleted all files of the log directory, but still can see space occupied by logical volume of this directory.

[root@MY-SERVER logs]# rm -f /opt/application/MYAPP/logs/*.log

[root@MY-SERVER logs]# df -hT

....

....

/dev/mapper/infravg-MYAPP_log_lv

              ext3    434M  393M   19M  96% /opt/application/MYAPP/logs

Solution

Step 1. Find out all the log files which are deleted but their occupied space is not released using lsof

[root@MY-SERVER logs]# lsof | grep logs

....

....

java   root   96ww   REG   6148 /opt/application/MYAPP/logs/my_tests.log.lck (deleted)

java   root   98w      REG   6150 /opt/application/MYAPP/logs/my_tests.log (deleted)

java   root  101ww  REG   6153 /opt/application/MYAPP/logs/jonas_wsdls.log.lck (deleted)

java   root  102w     REG   6154 /opt/application/MYAPP/logs/jonas_wsdls.log (deleted)

java   root  1w         REG   6145 /opt/application/MYAPP/logs/startup.log (deleted)

java   root  2w         REG   6145 /opt/application/MYAPP/logs/startup.log (deleted)

java   root  105ww  REG   6160 /opt/application/MYAPP/logs/startup-2015-10-06.3.log.lck (deleted)

java   root  106w     REG   6161 /opt/application/MYAPP/logs/startup-2015-10-06.3.log (deleted)

java   root  223w     REG   6171 /opt/application/MYAPP/logs/webservice.log (deleted)

su      root  cwd       DIR    3072 /opt/application/MYAPP/logs

grep  root  cwd        DIR   3072  /opt/application/MYAPP/logs

lsof   root  cwd        DIR   3072  /opt/application/MYAPP/logs

Step 2. Stop or Kill the related processes

Step 3. Check logical volume space again

[root@MY-SERVER logs]# df -hT

....

/dev/mapper/infravg-MYAPP_log_lv

         ext3    434M   11M  402M   3% /opt/application/MYAPP/logs