More about RAID

[scott_417]

If I understand it correctly, theoretically speaking, I can simultaneously have RAID 0, RAID 1, and RAID 5 on the same server, --correct?

Even if this is true, it is better we should either use RAID 0 + RAID 1, or RAID 5 on a server, but rarely in combination of all of them, --correct?

Finally, while we are talking about so many good things on using the RAID, does any one have some real experience that using the RAID saved the day? I mean in reality, how well does it turn out?

I would imaging that by employing six (6) disks alone, could cause some issue. Why? --imagine the six disks turning, spinning, whistling, and cranking, wouldn't that increase the chance of accident. I mean if there are six cars simultaneously running, the chances for something to go run among them is greater than just one car's running (the probability increased). Maybe this is not a right understanding, but still like to hear the folks out there to tell some real stories.

Thanks to share your experience.

Scott

[Steven Clementi · Accepted solution]

Scott:

Yes, you can effectively have 1 Array(or multiple arrays) with 3 different RAID levels for 3 logical drives.

It is acceptable to use any combination where your application's performance requires it.

Yes. I have had several servers have problems in the past several months where a drive just fails suddenly for no apparent reason. I just go in and swap out the bad drive and it rebuilds itself. The whole time, the system is up and running without a glitch. You can never truely know when someting freaky is going to happen like a drive failure.

Seems like you understand it right. The more hardware that is running, the greater the potential that something will fail, which is why RAID is sometimes necessary to lower that posibility of "hard" failure.


Assume you have a disk shelf with 14 drive slots. If you have 2 drives in bay 1 and bay 8, the chances of either of them failing is rather low, but there is still a chance. If you were to install drives into bays 2,3,4,9,10 and 11... you have just increased the heat in those sections, increased the potential RF interference, increased the noise (potentially causing someont to wnt to break something), etc... You have increased the potential for something to break.



Steven