Re: simple backup script - options

[Alvin Oga <aoga@ns.Linux-Consulting.com>]

On Tue, 2 Sep 2003, Marcus Schopen wrote:

> > 
> > Why don't you just use RAID to mirror your harddisk?

- dd is NOT backup ... its an easy way to get data corruptions
  when disk-A  has badblocks that are different that the badblocks
  on target disk-B
	- luckily, badblocks are rare and few now days

	- and dd limits you to roughly the same size partions
	on both ends otherwise, you have unused/wasted space

raid[n] is NOT backup ....  
	- raid does protect you from downtime if a disk dies
	and you can keep going for a bit with the other disk

	- have another disk failure and lose everything on all
	disks unless you know how to recreate data from inodes

raid1 does NOT save a copy of a file
	- erase it  .. and its gone from both disks
 
> The first harddisk is running in a raid (mirroring). But beside this 
> raid I'd like to have a backup to this second harddisk. Call me paranoid 
> if you like, but I feel better with this solution.

for the paranoid ..
	- backup daily from the last full backup to "daily backupdisk"

	- backup 30 days every week to "backupdisk 30"
	- full backup every week to "full backup disk"

	- backup 90 days every month  - to "backupdisk 90"

	dailybackup, backup-30, backup-90  and full backupdisks are
	all different disks on different server 

	-- assume that last weeks and previous full backups was bad ..
		- how many files did you just lose

various backup scripts
	http://www.Linux-Backup.net

	-- restore your machine from "bare metal" on an irrelgular basis
	to make sure "backups is working" 

	diff "ls -laR /current_system" "ls -laR /restored_from_backup"
	( or whatever way you wanna verify your restored system )

c ya
alvin
	
 
> > Saves you daily backups and gives you instant backup on failure. And IIRC
> > your system can keep on running 'on one tyre'.
> 
> Saluti,
> Marcus
>