Hard Disk Backup Question

[Bill Davidsen]

Ralph De Witt wrote:
> Hi All:
> I have a Dell Inspiron E1705 Computer with a 80 gig hard drive. I also have a 
> Western Digital 500 gig My Book External USB Hard Drive attached. I would 
> like to Back up the entire hard drive to a partition on the external drive. I 
> have very little knowledge of how to do this. I have always backed up to a CD 
> individual files after a data loss. I thought a auto backup routine would 
> work, but the computer may not be on when the backup would be scheduled, and 
> the external hard drive partition do not seem to want to auto mount so that 
> would not work. I am using the kde desk top. Could some one add to my 
> knowledge and help me out? TIA

If you want to make a backup of the physical hard drive, such that you 
could just replace the drive with an identical drive and recreate it, 
you need to boot from a CD, such as the Fedora rescue CD, and just copy 
the contents. Assuming that the external drive is sdb, mounted on 
/mnt/external (for example):
   dd if=/dev/sda bs-1M | gzip -3 >/mnt/external/2007-10-04-1410-image.gz

Note that the image must be restored to an identical hard drive, since 
it's an image of the whole disk. It might work on a larger drive, but 
you might not use, or even have access to, the whole drive.

There are various utilities to do this, g4u being popular. This has some 
of the same limitations, but is easy to use. Because it's based on 
netBSD (AFAIK) the drivers are not identical, but it can backup over a 
network using ftp.

There are commercial products which do this, use Google, I haven't used 
any in several years and can't suggest.

Finally, you can backup the contents of the critical data (or all files) 
using programs like rsync, or using tar, cpio, or star. These require 
manual partitioning of a replacement drive, restore, and rerunning grub 
by hand, but offer more flexibility.

You can also put an incremental backup program call in your shutdown 
sequence, to be sure you back up anything you have done in a current 
session.

Hope that's a useful overview of the possibilities, I'm not sure just 
what features you need, and there's always a tradeoff between 
convenience of restoring a single lost file and that of restoring 
everything.

-- 
Bill Davidsen <davidsen at tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot