Comments on: How computers store information…

By: colin

colin — Thu, 13 Mar 2008 02:43:32 +0000

Thanks, Dave – I’m going to set this up on a couple of my Linux servers.

Cheers

Colin

By: Dave Lane

Dave Lane — Wed, 12 Mar 2008 22:22:14 +0000

The best way to do backups, on Unix-like systems (Mac OS X, Linux, Solaris, etc.) at least (not sure if this works on MS systems) is to use “rdiff-backup“. It works by syncronising selected files with a backup archive – creating a “mirror” of your files – either on the same computer or across a network (in which case it transfers the data compressed and encrypted).

What makes it different and better than other systems is that any time it adds, deletes, or updates a file or folder on the mirror, it retains “deltas” (i.e. the change or difference) to the previous version of that file or folder. These deltas can be held for any number of days, limited only by your disk space.

Keeping deltas means that, in addition to having a mirror of your file system as of the last backup, you can also recover files or entire directories even after they were altered or deleted, so long as they were backed up on some previous day… Incredibly powerful.

Rdiff-backup is, of course, open source and completely free to use.

Cheers,

Dave

By: it.gen.nz » What exactly is a kilobyte? (or a Megabyte, or a Gigabyte)

it.gen.nz » What exactly is a kilobyte? (or a Megabyte, or a Gigabyte) — Tue, 11 Mar 2008 19:20:21 +0000

[...] is a lot of confusion about this out there as I said on the radio last week, but the usual definition is 2^10 bytes, which is 1,024 bytes. Here’s a cartoonist’s [...]

By: * Colin explains hard drives, in TiKouka

* Colin explains hard drives, in TiKouka — Fri, 07 Mar 2008 18:32:21 +0000

[...] [Via : it.gen.nz » How computers store information ….] [...]

By: Robin

Robin — Thu, 06 Mar 2008 23:46:07 +0000

You state that “you should never ever store backups as compressed files.” My IT ‘expert’ has provided me with a backup program which zips the files to a CD which if necessary can then be read on any PC and unziped not like Windows which requires the original PC to restore. Is this not a recommended system.

By: Christopher

Christopher — Wed, 05 Mar 2008 23:20:17 +0000

You wanted a backup method for Linux.

The ‘traditional’ way is just to copy the precious files to the other medium, automatically or by hand as desired.

the rsync utility is useful to avoid copying unchanged information.

‘The Advanced Maryland Automatic Network Disk Archiver’ is a useful back-up package, one of several dozen.

http://www.amanda.org/

Remember that you should never, ever, store backups as compressed files.