Moslty this is caused due to buagent not running. Even if we tried to restart buagent,it will not start and status will be showing “buagent (no pid file) not running”

Check /var/log/messages to see whether kernel module is missing or not. If it is showing any missing kernel modules, you can install kernel modules by simply running  r1soft-cki in the command prompt

# /etc/init.d/buagent restart

# /etc/init.d/buagent status
/etc/init.d/buagent status: buagent (no pid file) not running

# r1soft-cki
Checking for binary module
Waiting \
Complete.
Saving kernel module to ‘/lib/modules/buagent/backupdriver-cki-2.6.18-028stab070.4.ko’
Kernel module is now installed.

# /etc/init.d/buagent restart
/etc/init.d/buagent restart: buagent not running, trying to start
/etc/init.d/buagent restart: buagent started

If you are still facing issues, then you may need to try reinstalling the buagent.