Not to be pedantic, but there are decisions to be made at multiple levels. On 
the physical level, I think CD/DVD is the poorest for all but passing files to 
friends or AV media, where errors are overlooked. The industry is moving 
towards using hard disks for backup, and flash drives are too small for 
anything but bits and pieces (a modern day floppy).

Then, how will you use the hard disks? One has to prepare for the possibility 
that they could fail, AND could fail while making the backup (so just a copy 
command isn't good enough). Since failures tend to follow a bathtub curve, burn 
in new drives with something like SysInternals sdelete with multiple passes. 
It'll keep the drive busy and use the whole platter(s). Go for a few days 
continuous.

Then, are you just taking a current snapshot all the time, or are you going to 
  look for that accidentally deleted file from 2 months ago? How long do you 
want to keep them? Some should be kept off site - weekly or monthly or yearly, 
depending on your paranoia. More hard drives... An rsync mirror is a very 
different resource than a complete backup from 2 months ago. If you will focus 
on pulling old files off and replacing deleted ones, a mirror or an image 
backup isn't as useful as a file-by-file backup. Remember windows uses locks 
and locks system files for reading too. A full backup that's usable means 
taking it offline. Of course, this doesn't include revision control type 
methods where every version is saved. The finer points of each define their 
usage, but one can engineer a process under combinations to fit one's needs.

I've made a short list of 'core' apps that are very useful in many situations 
concerning file backup situations:

Thanks to this list, and after testing, 7-zip seems the most verstile and 
useful zipper. Command line is best for zipping, and the portable-apps version 
is convenient for getting stuff out. Optional, depending on your methodologies.

ERUNT is a very easy and reliable registry backup program with tools to restore 
the registry as well in one click. Can run from command line too. I suggest a 
daily reg backup from cron (yes, there's a pc cron) and on boot. That way, if 
you mess up the registry, you can restore it. One can pretty much turn off the 
system restore bloat this way.

http://corz.org/windows/software/checksum/
Very useful and easy hash generator/checker. One can even create a shortcut, 
drop the dir on it, and it will create either a root hash, per folder hash, or 
file by file hash. Tested on 100,000 files at a time and worked fine. Same for 
a verify shortcut.

http://ice-graphics.com/ICEECC/IndexE.html
This creates ECC files and has convenience settings for CD and DVD. So, if your 
hard disk or DVD start to go bad, this will use ECC code to replace the missing 
bits. Very handy, useful, and compute intensive.

http://www.xs4all.nl/~edienske/abakt/index.html
This is a very detailed front end for setting up a zip (as in a whole drive 
zip) and is 7-zip aware.

http://www.dfincbackup.com/freeware.htm
This will peel off recently changed files, per an instruction set, and zip them 
or whatever you want done with them. Lots of ways this function can be done, 
but this is an easy set-and-forget tool if you have other users.

Don't forget encryption. The backups can get physically stolen too, or if 
you're in a country where the police like to take PCs, you might encrypt the PC 
and not the backup. Not a good choice - the backup could be worse, depending on 
what you save... Axcrypt is a good file encryptor, open source, etc., and while 
it will do lots of files at once, zipping, then using it, might be good.

For images, Clonezilla is good, and their boot disk with Gparted is invaluable, 
but it can have problems if writing the images to an ntfs drive, or ntfs 
compression or encryption is on. BartPE is invaluable for a windows pc too. I 
can't tell you how many unbootable pcs I've fixed with it. Booting with it will 
let you get to all files, since none will be locked. If you run with portable 
type apps, it's very easy to include them on the cd or one can run them from 
any drive while booted into BartPE, since there are no demands on the registry 
with a portable app generally.

One then is left with one's personal goals to sort out and apply these tools 
with lots of hard drives. ;)

-Skip



Cedric Chang wrote:
> So what tis the best long-term backup method ?
> paper ?
> cc
> 
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