Friday, August 24, 2007


RAID is a computer acronym meaning "Redundant Array of Independent Disks." Wikipedia. In this case we're talking about "mirrored" disks, one of the simplest RAID configurations, where two identical disks contain identical data so that one can continue operating if the other fails. Since they contain the same data the second disk doesn't add any disk capacity, but it does add reliability. Pros:
  • The hard disk is MUCH less apt to crash. Only people who have experienced a crash can fully appreciate this.
  • Perhaps I can get away with less backup, e.g. only back up the most sensitive data.
  • Or, I can buy a THIRD drive and hot-swap it, so the swapped-out drive is the backup.
  • I'd enjoy the experience of setting it up and using it.
  • It's more expensive: I need two drives, not one, and the motherboard (which manages the drives) costs a little more.
  • The drives will make twice as much noise. Hmmm.
  • It doesn't solve ALL backup problems: If I accidentally permanently delete a file, it will be gone on BOTH drives; if lightning hits the computer it could easily take out both drives.
I'm leaning toward RAID, as you may have guessed. But haven't decided yet for sure. Seems like overkill for a simple office computer. But then again there's the experience of it ...

Here are some other features of the computer that's starting to come together:
  • Sonata III 500 case, with 500 W power supply. This is the outer box for the whole thing, and this box is quiet with plenty of power available.
  • Intel E6750 dual-core processor, 2.66 GHz, 1333 front-side bus, with Intel motherboard to match. This is two very fast processors in one. By the time I get going on this, the E6850 may come down in price, even faster.
  • 2 Gb of 2-channel DDR2 memory, 800 MHz. Expandable to 8 Gb they say, but the chips for that don't exist yet; 4 Gb is the max.
  • Seagate 320 Gb SATA-300 drive(s). Big enough for me.
  • Sony AWG170S-B2 18x DVD read/write.
But everything is still in pencil. Absolutely everything. Meantime, though, I did a little pricing of the materials lists for WITH RAID and withOUT RAID. Here are very preliminary materials lists: I'm totally new at this, a complete novice. If there is anyone out there reading this blog with an idea or a word of caution, I'd love to hear from you.


Anonymous said...

Remember that a mirrored RAID configuration will not help you against:
- Viruses
- Malware
- Filesystem corruption
- Deleting files on accident (as you said)
- ... or anything else that could happen to your files in day to day use of your computer.

Basically, RAID only helps you against complete hard drive failure (as I understand it). If that is a significant concern for you, RAID might be the way to go. Otherwise, you could just get a second drive for regular backups.

Don said...

Thank you - good advice.

Current plan is to use mirroring to guard against disk failure, and to perform monthly backups to a third identical drive as a hedge against those other risks.

I'm hoping that I can do the backup by simply taking one of the mirrored drives off line (as the backup) and re-mirroring to the third drive. But I'll see whether the MOBO manufacturer makes that easy or not.