RAIDing party!

I wish I could have picked a less expensive hobby.

So my friend and I were talking about RAID a while ago… For you uninitiated geeks, a RAID is a set of multiple drives that interact with each other on some level. It’s intended to preserve data, but there are modes that promote speed over preservation. Like, say, RAID 0 will take two drives and spread files out between the two drives, meriting a literal read time of 2x the amount of a single disk. RAID 0 increases speed for each drive, but each drive also increases your chances of failure. Since RAID 0 spans a single file over multiple drives, when a single drive fails, you lose everything, period. RAID 1 is a mirror! You have two drives, but you only use the space of 1 drive, and the 2nd drive is an exact duplicate. The ultimate in fault tolerance. One drive dies, use the other, buy a new drive, recreate the mirror. Data is secure! Then there’s RAID 5 which is a bit more interesting. Basically, you have a minimum of 3 drives. The equivalent of two drives are used for data, and the equivalent of one drive is used for error correction. The error correction information is used for when a drive fails. When you replace it, the RAID interface can recreate all the missing information. The nice thing about this is that the data and error correction information is spanned across all the drives, so there’s no single point of failure. This is probably the most popular out of the three basic RAID types when it comes to data preservation.

Now that I’ve explained all that, let me put a little word in for a nice RAID calculator I found. I knew there had to be some formula that would determine how much space was available for RAID 5, and I was right! Since all the drives have to be the same size in RAID 5, the formula is basically ((DRIVE SIZE times DRIVE AMOUNT) minus DRIVE SIZE). In other words, add all the drives together, and then subtract one for the error correction information. So a RAID 5 of three 350GB drives would get you precisely 700GB of space. As you can see, the more drives you add to RAID 5, the more space you get. The ratio stays the same, but you have more to work with. I think that if I ever actually used RAID 5, it would be three gargantuan drives. Probably 500GB or possibly 750GB… But, then again, the Seagate Barracuda series (which I adore as a drive) now comes in a lovely 1TB. Seriously… three 1TB drives in RAID 5. Expensive, but you wouldn’t have to upgrade for a very, very, very, very, very long time. $250 a pop, right now, so… That’s $750 right there in hard drive space. I would rather spend that on two video cards.

So my conundrum emerges from a little issue with read/write speeds. Remember that dream computer I built a while back, but then got the smackdown by college and couldn’t finish my work? Yeah, well, the price dropped from a whopping $3250 to a measly $1950. But! The point is… It’s a gaming system, and it’s going to be built for pure speed, right down to matching bus speeds on the RAM. As such, I am going to have multiple drives, as I have always done with my desktops, sans the Linux server. One drive for the operating system and one drive for programs and documents. Yes, as a matter of fact, I installed all my games and applications on the second drive and I remapped My Documents there, too, so I can literally reinstall Windows and everything is still intact. However, I soon learned (as a true geek would know by just this second line) that the Windows Registry threw a wrench into that plan. I really should have known it before I started doing it, but I didn’t… Even though all my programs were safe, they still needed to be reinstalled, more often than not, because of the Registry. (Or, even if they didn’t, I wanted to do it anyway, because I’m obsessive-compulsive like that.) So… It didn’t work out as well as I planned, and I relegated that drive to pure document storage. Moves and music and projects. Applications on the OS drive, documents and projects on the data drive. Worked like a charm.

But… I decided to look into RAID and I started seeing all these notices and warnings about RAID read and write speeds. RAID 5 seems to have it the worst (of course). Since it has all the error correction checksums, writing files to the drive is excessively slow, while reading is also negatively impacted for the same reason, but not nearly as much. So you get an impressive fault tolerance system, but it’s not nearly as fast as, say, the completely unprotected RAID 0. However, I’m wondering if this RAID 5 performance hit is still better than operating off a single drive? In fact, I’m starting to wonder if RAID is even worth the investment as far as a gaming system goes. I mean, for issues of speed, anything but the dangerous RAID 0 is a no-go. But do I want to sacrifice fault tolerance just so I can load a game level 5 seconds faster than everyone else? Right now, I’m thinkin’ no. If I do RAID, it’ll be RAID 5, because I’ve been around this industry long enough to realize that losing data is a nasty experience… Even losing my bookmarks is a bad deal, much less losing an entire drive. Technically, I’ve had that happen a few months ago. My data drive began making clicking noises and it got incredibly hot and smelled terrible and Windows stopped reading it entirely. (I was able to get my sensitive information off of it using Linux, and then got it working in Windows again, but still… I know what it’s like to lose data, even for a fleeting moment.)

But then there’s my geeky side that enjoys screwing around with the dark depths of my computer and I’ve been known to cause some… Er… Problems that required a complete format and reinstallation. I was prepared for it, of course, but it’s happened. That is one of the nice things about separating the OS from your data. But with RAID 5, it’s going to put two huge drives together and treat them as one, so if I reformat it, it’s going to wipe everything out, and I don’t know if I like that idea. Having two separate drives for that reason is really nice, indeed. So my dilemma is… dangerous but lightning speed RAID 0, or slow, but absolutely fault tolerant RAID 5? Is RAID 5 faster than a single drive? Is it faster than two separate non-RAID drives? Do I even want RAID? Do I want to simply have 2 drives, one for the OS and one for data and leave it at that?

Or… How about this? A separate set of portable, external drives in RAID 5 for all my data, plugged right in to FireWire or eSATA? If I did that (which is, honestly, a much better idea that I just came up with around 10 seconds ago), it would completely forgo the problem of “where do I put my most sensitive data?” Then it would simply be if I wanted two drives in RAID 0 for that ultimate speed increase, or three drives in RAID 5 for that ultimate fault tolerance. But, honestly? If all my good stuff was on an external RAID 5, I could very easily just pick two drives on RAID 0 for the massive speed increase and if something goes wrong, I would only have to reinstall Vista and my programs. Unless, say, I didn’t want to bother with reinstalling Vista when a drive dies. But, honestly, this is Windows we’re talking about. Even though I’m in love with Vista, I still realize that clearing it off every now and then is a good idea. Doesn’t need to happen nearly as much as pre-2000 systems, but it’s still nice to do sometimes.

You know what? I think I just answered myself during this post. I think that I’m going to invest in a nice, external RAID 5 contraption that sports a high-speed connection that I can use to connect to whatever I want, and then shoot for ultra-fast RAID 0 on my desktop. I would put all my music and special, one-of-a-kind, commit-suicide-if-I-lost files on the RAID 5. The things that really don’t need to rely on speed. Wow… I think this post was really informative! I should do this more often.

One thought on “RAIDing party!

  1. Paradox

    RAID, backups, something to keep the data intact…

    I’m still trying to recover files from an external HD after the USB controller fried and corrupted half the drive :(

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