BACKUP THE LINUX SERVER

Which servers to backup
Which directories/files to backup
What is the Backup media
Backup Failure Modes
Testing Your Backups

OffSite Backups

Backup Servers
Which Servers to backup
Pull the ethernet cable to it....and see what happens..

Backups should be on a different server than the server/data you are trying to backup
protect against the server wiping itself out and its backup
Backup all PCs on one LAN/hubb to a local backup server - minimize traffic
Backup all Local backup servers to the other Building's Backup server and vice verss
Backup Directories
Most of the "System" directories and files are already on the installation cdrom
Most of the "Updates" you applied are already scattered at the various mirrors on the internet
Which directories to backup is dictated by the size and topology of your network
Backup of a single server is significantly simpler than backup of different servers
www, email, firewall, ftp servers, home servers, file servers, etc


Which directories to backup is dictated by the partitions used to install
move system config files into /etc or /usr/local/etc so that its backed up

If you can recreate your entire system on another disk...you've selected the "right directories to backup"
you should backup "user data"
/root /etc /home /usr/local
you should optionally backup log files and pending emails
/var/log /var/spool/mail
 Backup Media 
The number of servers and size of your data dictates your backup media
Backups onto floppy -- good for Full backups of /etc

Backups onto Zip -- good for backups of 200Mb

Backups onto CDR -- good for backups of 600Mb

Backups onto DVD -- good for backups of 4GbMb

Backups onto Tapes -- good for backups of up to 40-80Gb, and more with tape libraries

Backups onto Disks -- good for 500Gb -- xxTeraByte Raid5 Backups


NEVER backup your data to the same partition, nor same disk
if you lose the disk...you do NOT have any backups


Backups are best done to a DIFFERENT server
protect your backups from hardware flakyness and random power surges etc



Tape and CDR backup media REQUIRES you to change it daily/weekly...
if you forget, you lose the previous backup... and you may also lose todays incremental backup data too

You have to clean the tape head regularly

You can lose one of the daily incremental tapes, or someone can walk out with your corp data
Restoring a file from tape can be a slow process ( hours and hours )


One 20Gb can hold about 1-2 months of full and incremental backup of another 20Gb disks depending on data amd backup methodology


Backup Failures 
Backup Failure Modes