On Sunday, May 06, 2012 08:51 AM Carlos E. R. wrote:
On 2012-05-06 11:25, phanisvara das wrote:
i'm afraid i'm overlooking something obvious, that's why i'm asking here, where many have much more experience with this type of thing.
You need both raid and a backup, and IMO it is more important the backup.
If you make a goof and delete something, the data will be deleted on all the disks of the array. If you have a good backup strategy, you can recover deleted files.
It is as simple as that.
All that you do is done to the entire raid array. Any bad thing happens to the array - you are protected only from one type of failure: a disk failure.
Note that with rsync you can have a history of changes: the new directory has the new files, and hardlinks to the old files that exist in the previous directory.
But doing backups every 15 minutes is excessive wear. You would need a third disk with daily backups, and powered off the rest of the day.
fwiw on my primary machine which requires 100% uptime I use RAID with an additional disk which I mirror with rsync as a failover. In my rsync script I use rsync parms to retain a different fstab and menu.lst which enables it to be bootable at any time. I run the script via cron during lunch and in the evening, so it's not a real time mirror but it's close enough. I also maintain a copy on another machine on my gb lan as protection against a catastrophic failure (i.e., not just disk failure) of the primary machine. Cron runs this rsync script once every evening. Storage is cheap nowadays. Once this is all set up, everything is automatic and I don't have to pay any attention to it, other than the scripts mailing me a message indicating success or failure in the run. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org