Tuesday, November 29th, 2005, 6:46 pm
RAID Redundancy
AID stands for Redundant Array of Independent (or Inexpensive) Disks. As yet, I find RAID somewhat redundant, at least in my individual scenarios and for my personal purposes.
RAID is associated with backups on multiple disks, which in turn enables easy data recovery. The disks may also be distributed across geographically isolated and thus independent places. RAID does not directly cater for synchronation of data, applications, settings. That, for instance, is one of the powers of on-line services and network-hosted environments. This, as a matter of fact, is what pushes computers towards becoming relics.
One question to consider in RAID is the target of a write/read operations. This point refers to where data should be fetched from or save onto and how changes should propagated among the multiple disks. These issues are easily resolved in the following way:
Let us look at this conundrum, which is flawless management of files across computers. The confusion over where data gets stored and fetched from can be resolved owing to remote login. Assuming we speak of high-bandwidth networks here (100Mbit LAN in my case), the ‘cost’ of using SSH bandwidth is almost negligible. Even 10Mbit connections would give you a very responsive UI behaviour over the network. I know this because I tried it. The exception are cases where you stream many large frames over the network (e.g. video, games).
I have never looked deep into RAID technologies. Why not just scp
(or rsync
) the entire content of a hard-drive periodically? I maintain files on just a single machine, which I always SSH to from elsewhere. Its contents get mirrored on two other remote machines. Files that change on a daily basis are backed on the SAN overnight using cron jobs. This simplifies life a great deal. I still see no compelling reason for using RAID, especially with the existence high-speed networks.
As for Web site backups, these can conveniently be downloaded unless an automated job is set up, which is something I hope to do one day.
Related short items:
- Basics of Data Recovery (XHTML presentation)
- Mail Backup and Restoration
- Backup Fallacy