Source Jockey

A RAID is an abbreviation for “Redundant Array of Inexpensive Disks” or “Redundant Array of Independent Disks”.  They come in a few different configurations, and can be extremely useful, depending on your use.  I’m blogging about it today because a RAID saved my dad a ton of work, and a RAID could save you, too.

Most desktop computers have only one hard disk drive, or HDD.  (Don’t confuse the hard disk drive with the CPU, or the computer case itself.)  An HDD is about 4″ wide, 1″ tall, and 5.75″ long, and is generally inside the computer case.  This is where everything on your computer is stored, from the operating system (Windows, Mac OS X, Linux, etc), your programs (Microsoft Office, Photoshop, your internet browser), and your documents.  Generally speaking, HDDs, especially in desktops, are pretty reliable.  Every once in a while, though, one fails.  If you only have one hard drive, and you haven’t made backups, you are up a creek.  You might lose your data.

So RAIDs give you a way to prevent total failure if you lose a hard drive.  There are seven types of RAIDs, the most common being RAID 0, RAID 1, and RAID 5.  RAID 0 is actually NOT technically a RAID because it distributes your information across two drives.  If you lose one drive, you lose half your data, and you’re screwed.

RAID 1 is a mirrored configuration; all the hard drives in the array have the same information.  If you lose a drive, you simply replace it while the other one(s) contain your information.  The problem is, you have two hard drives with the space of one.

RAID 5 is pretty neat; you only lose one hard drive of space across your configuration.  (If you have 3 drives, you have the space of 2.  4 drives, the space of 3.  5 drives, the space of 4, etc).  If you lose a drive, the RAID rebuilds your information based on parity data it stores on the other drives.  (Just hope you don’t lose more than one drive at a time!!)

My dad had a RAID 1.  So when he told me he was getting the “drive failed” message, we just put a new drive in, and it reconstituted itself from the other drive.  The swapping process took 2 minutes, the interacting with the software took another minute or so, and rebuilding took about 40 minutes.  Not bad.

Make sure you use a backup, or have a RAID, or both.  It could save you.

This entry was posted on Friday, June 12th, 2009 at 5:28 pm and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.