To RAID or not to RAID

[Disturbedguy]

Hey all

I have been talking to a friend of mine and has suggested that I use RAID to get the best out of my machine.

I know there are different types of RIAD, from 0 - 6 according to a quick look at recap on Wikipedia.

Now, my question is which RAID do i use, my friend has recommended RAID 0 (Striped) but the obvious problem with this is if one drive fails I lose everything but theres an easy solution to that which is backup regularly and its advantage is the increased speed it offer.

But I know there are others that provide fault tolerance and redundancy.

The thing I do understand is that when and if I do choose to RAID I will have to format my drives.

The only thing is I dont really fancy reinstalling everything again, I have a CD with a program that will allow me to take an image of my drive, install that on a clean copy of windows which solves that problem.

So I guess what am asking is, which version of RAID do i want?

[peterb]

RAID 0 - loss of data if one drive fails, extra heat, power drain. Marginal increase in read speeds un der certain conditions - large data base acesses etc, little increase in write speeds, but write performance can be worse.

RAID 1 - mirrored drive - redundant data - if one drive fails, the other has all the data, and when the faulty drive is replaced, it replicates the data across. Good for servers when reliability and uptime is important. More power used, more heat, and two (sy) 500GB drives still only gives 2GB. Not a substitutes for backing up, because another failure causing disk corruption will still corrupt both disks

RAID 3 - RAID 0 with a parity disk - gives some protection to the RAID0 array, but needs theree disks. - Not much used.

RAID - 5 Data stiping across disks, with a parity disk. Can have any (reasonable number of disks - storage capicity in total of the disks -1. Commonly uses 4 or 5 disks.

Google for more comprehensive informatoion.

Worth it for a home installation? No IMHO - except possibly RAID 1 for a file or web server where reliability is important - but to repeat, it is not a backup solution, and the RAID needs to be monitored so that if a drive does fail, it is detected and replaced before the other one fails. "A hard drive is a mechanical device - it will fail - the only question is when"

[streetster]

the options that are usually available on a 'home' machine are:

RAID0 - striping (performance) (2disks)
RAID1 - mirroring (backup) (2disks)
RAID0+1 (or 1+0) striping+mirroring (4 disks)
RAID5 - mix of striping+parity (3-4 disks)


I've got a RAID0 array.

I the argument "if one drive dies you lose your data" is rather irrelevant, as if you were not using RAID and your drive dies. you lose your data. The only difference is that you're twice as likely to have a problem! But anything important should be backed up anyway...

Have a read around, you will either want RAID0 or RAID1. Depending on whether you want a (slight) increase in performance, or a cloned backup of your harddrive.

[Fraz]

Frankly I wouldn't bother. It's just not necessary for a home system, unless you want to do it for the purposes of waving your e-willy...

[streetster]

*waves e-willy*

[Fraz]

*waves e-willy*

I can't see it!

[Disturbedguy]

I wasn't thinking of using RAID for backing up, i was thinking of using it for the apparent speed increase it provides.

[streetster]

I can't see it!

it's just a stream of 1's and 0's floating through the air... and its massive... honest....

[Disturbedguy]

wait, wouldnt it be all 1's if you were turned on and all 0's if you werent turned on?

So the only way you can get 1's and 0's together is if you have a semi.

[Splash]

I the argument "if one drive dies you lose your data" is rather irrelevant, as if you were not using RAID and your drive dies. you lose your data.

While that's true there's the extra cost involved (both in terms of the second disk which you need for the array and the power required)

[Fraz]

While that's true there's the extra cost involved (both in terms of the second disk which you need for the array and the power required)

Plus you double your likelihood of a disk failure, if you've got two disks in AID0 (not RAID0!)

[finnrogers]

I use RAID 0 and I can honestly say there is a definate improvement in load times for games and copying large files or large quantity of files. The whole "you're twice as likely to lose all your data if one of the drives fails" argument is pretty irrelevant IMO since the only time I've ever had a drive fail was due to a power surge which actually killed all 4 of my drives at the same time (I used a surge protector now!) and if you're going to be keeping backups like you said, then it's not a problem. Personally, I also like the fact that my two 160gb drives appear as one 320gb drive too and this becomes even more usefull when you grow the RAID to 4 or more drives - for example keeping 100s of large avi files in one folder rather than some on one drive, some on another, etc etc... Not that important I know, just something that I prefer personally.

The only downside I see with RAID is having to install the RAID driver during the Windows setup. With Vista this is a piece of pish, since it allows you to use a USB stick with the drivers on it, but under XP you need a floppy drive which for some people (like me) means having to actually buy a floppy drive and install it just to load the RAID drivers... irritating to say the least.

Ideal setup for me would be a RAID 0 setup for the OS, games and programs for performance, and a stand alone massive drive for file storage.

I say go for it!

[kalniel]

AID0 (not RAID0!)

Excellent, that gives me the chance to make the following pun:

"The R in RAID0 is redundant"

[Fraz]

Excellent, that gives me the chance to make the following pun:

"The R in RAID0 is redundant"

*groan*

[Splash]

I use RAID 0 and I can honestly say there is a definate improvement in load times for games and copying large files or large quantity of files.

I don't think anyone is disputing that there is an improvement, but it's certainly not as big an improvement as the OP may be expecting.

The whole "you're twice as likely to lose all your data if one of the drives fails" argument is pretty irrelevant IMO since the only time I've ever had a drive fail was due to a power surge which actually killed all 4 of my drives at the same time (I used a surge protector now!) and if you're going to be keeping backups like you said, then it's not a problem.

A hard drive is a mechanical device, and as such is subject to the wear and tear associated with this. As has been pointed out it WILL fail, it's just a case of when. Is he going to be backing up the entire array, or just certain files?

I also like the fact that my two 160gb drives appear as one 320gb drive too and this becomes even more usefull when you grow the RAID to 4 or more drives

To be clear - most RAID cards will not allow you dynamically resize an array (ie just add another drive to increase the array size) - you would usually need to backup, trash the array, create and format a new array and then restore data to it. Before anyone comes back with "I can do this on my PC" I'll repeat that word - MOST.

The only downside I see with RAID is having to install the RAID driver during the Windows setup. With Vista this is a piece of pish, since it allows you to use a USB stick with the drivers on it, but under XP you need a floppy drive which for some people (like me) means having to actually buy a floppy drive and install it just to load the RAID drivers... irritating to say the least.

The big downsides for me are more based around the expense, and the fact that unless spending cash on a hardware solution it means that your CPU will be taking a hit. I doubt that the OP is looking at 3ware etc as yet...

Ideal setup for me would be a RAID 0 setup for the OS, games and programs for performance, and a stand alone massive drive for file storage.

I say go for it!

I've got a couple of boxes with RAID5 arrays - one is a virtualised box which hosts my DC and mailserver, the other is my file and media server. My desktops are all JBOD.

But that's just me - for me it's not worth RAID in a desktop however ymmv. So long as you're keeping good backups you should be fine.

[Disturbedguy]

Bah I dont have a floppy disc drive and dont fancy buying one just to install some pigging raid drivers lol, any other way around it?

Im not expecting that big an increase, just an increase really, thats what ive been told anyway.