Adjusting qmail queue time / lifetime

set the queuelifetime:

# echo 86,400″ > /var/qmail/control/queuelifetime

# /etc/init.d/qmail restart

The above example is for 1 days (qmail needs the time length in seconds). Just take the days and multiply by 86,400 seconds to get your result.

BackUp and Restore MBR after Windows Crash

Step 1 : Login as a root user.

# dd if=/dev/hda of=/dev/fd0 bs=512 count=1

This makes an exact copy of the MBR of the first hard drive (hda – you need to replace this), copying it to a floppy disk. You can boot directly from this floppy, and see your old boot menu. You can restore it by switching the “if=” and “of=” (input file, output file) parameters.

 

If you don’t have a floppy drive, you can back it up to a file using below command.

# dd if=/dev/hda of=/home/Username/boot.mbr bs=512 count=1

Use your Linux distribution’s installation CD to boot into rescue mode and restore it with below command.

 # dd if=/mnt/hda5/Username/boot.mbr of=/dev/hda bs=512 count=1