Cannot write to file as root

There is a file on one of the servers I manage that i cannot modify with the root account. This file resides within a web application and contains configuration settings; I suspect that a previous admin may have done something to prevent the file from being overwritten.

Attempts to delete the file result in 'permission denied' type messages, though the file has write permissions. It also does not show up in the output of lsof and its inode is not listed in /proc/locks. The file resides in an ext3 lvm volume stored on the local hd. SELinux is disabled.

Does anyone have any idea what could be preventing write access?

Solution 1:

Look at it with lsattr, then use chattr if necessary to change the flags. It probably has the immutable attribute set.