6.18.2008

Backing up the back up.

Western Digital, maker of drives for years now, has released the MyBook Mirror edition. It's an external hard drive (yawn) that houses 2 drives (double yawn) and includes a Raid 1 card (a wuh?). RAID (Redundant Array of Independent Drives) comes in many flavors and it's main purpose is to protect data by creating some degree of redundancy. One of the simplest ways to do this is to copy the same data onto 2 drives at the same time. One drive dies, the other lives on with your data. That's called RAID 1.

What's the big deal? Well, I have an external drive, and it holds my photos, music, hopes, dreams, etc. Because drive space is so abundant, I don't have copies of these photos and songs elsewhere, but if the drive goes down, so does my data. Enter the RAID 1 of MyBook Mirror. If 1 drive dies I am good.

My question: to you techies - Drives generally die from either a power surge or some internal failure (many times mechanical). If both drives are housed in 1 unit, a surge will kill both, no? Is there a better way to get mirrored data without having to remember to back it up all the time?

4 comments:

Ari said...

I think internal failure is the most common way for a drive to fail, rather than due to a power surge. Also, even if there is a power surge, it might only affect one drive, if only one drive happens to be active at the time. In any case, if a drive fails either due to internal failure or to a power surge, the data should generally remain intact on the disk platters, so it is recoverable given the right equipment. Thus, the RAID feature is only useful insofar as it (in some cases) saves you from having to bring your disk to a data recovery expert.

However, keep in mind that a magnetic field can actually destroy the data from the disk platters. So, if the 2-disk unit gets placed in a magnetic field (or gets physically destroyed, such as in an explosion or a flood), then RAID does you (virtually) no good! (Although to the extent that portions of the data remain intact, having 2 identical copies can increase the likelihood of partial recovery, I suppose).

Jeremy said...

time machine
once you go mac
you never go back

Matt said...

take your data.

make a copy.

send it to a friend who lives out of state.

have said friend put it on his network.

rsync between your local and remote backup.

thegameiam said...

I've never had a disk fail due to power surge - it's always been shock trauma that killed mine. However, one thing to watch out for in RAID arrays is corruption of the RAID controller - that can chew up both copies at once.

ShareThis