How to setup RAID 1?

Girdag · 23 Feb 2007 at 15:53

I'm thinking about setting up a RAID 1 array on a new computer. I'll probably be using 2 Western Digital Caviar 320GB drives (the new AAKS models). I understand I'll see a performance drop, but these drives will be used for storage, rather than any programs, and as I've got quite a good bit of data I don't want to lose, I figured it would be a relatively cheap way of giving me a bit more security in case of a hard drive failure (if my programs drive goes down, I can just reinstall, but if my data's lost, then we have problems).

What I was wondering was whether I need any extra hardware to do this. I'm fairly (OK, completely) new to building PCs (I have a reasonably good theoretical knowledge, but no practical experience), so if this will be massively complicated, then I won't bother, and just get hold of an external hard drive, but the automatic backups of my data would be very useful. So, how hard is it to do, and what would I need?

LewisStuart · 23 Feb 2007 at 16:12

Does your new computer (motherboard) have SATA RAID built in? If not you'll need an add in card.

Also you won't see a performance drop using RAID1, it will be the same speed as using a single drive.

Girdag · 23 Feb 2007 at 17:22

LewisStuart said:
Does your new computer (motherboard) have SATA RAID built in? If not you'll need an add in card.

Also you won't see a performance drop using RAID1, it will be the same speed as using a single drive.

Probably shoulda checked that, yes it does. Excellent. Also excellent to the second piece of news as well.

rpstewart · 23 Feb 2007 at 17:40

You may see a performance drop for writes, I tried RAID1 at one point on an NVidia NForce4 based board and while the read speed was fine the writes were only about 25-30Mb/s, about half what I would expect from a single drive.

Mind you for storage writes aren't that important.

WoZZeR · 23 Feb 2007 at 22:43

I've just set my new Shuttle up with 2 WD 250GB SATA2 drives in RAID 1 and they seem ace, no slower than 1 drive in the real world. I was expecting a bigger performance hit really being used to the RAID 0 Raptors, so pleasantly surprised.

Mind you a full NTFS format for XP was mindnumbingly dull.........

With my PC it was very easy to setup:

Select RAID in the BIOS

On exiting the BIOS a RAID Menu appears:

Label your Volume

Select RAID 1

Select CREATE VOLUME

Bingo, Bob's your uncle.

For XP you need to ensure you have the SATA Drivers for your M/B on a floppy disc, it asks for them as it installs, I'm not sure about Vista.

And that's all there is to it.

ste_bla · 23 Feb 2007 at 23:43

Girdag said:
I'm thinking about setting up a RAID 1 array on a new computer. I'll probably be using 2 Western Digital Caviar 320GB drives (the new AAKS models). I understand I'll see a performance drop, but these drives will be used for storage, rather than any programs, and as I've got quite a good bit of data I don't want to lose, I figured it would be a relatively cheap way of giving me a bit more security in case of a hard drive failure (if my programs drive goes down, I can just reinstall, but if my data's lost, then we have problems).

What I was wondering was whether I need any extra hardware to do this. I'm fairly (OK, completely) new to building PCs (I have a reasonably good theoretical knowledge, but no practical experience), so if this will be massively complicated, then I won't bother, and just get hold of an external hard drive, but the automatic backups of my data would be very useful. So, how hard is it to do, and what would I need?

Don't take this personally but i have this massive gripe about how people thing raid is soo good.. it doesn't protect against hackers, viruses, power surges, fire and so on...

Why not get a external drive (ie usb) and back up the data one a week and place that disk in a safe place? Might be a few more £ but to me its a lot safer

WoZZeR · 23 Feb 2007 at 23:48

I couldn't agree more, I still write important work files to DVD once a week, but when HD's are so cheap a little bit of extra protection isn't hard to justify, I also use a UPS, the electricity over here is erratic at the best of times.

tsinc80697 · 24 Feb 2007 at 02:54

for RAID1 do you have to format both drives?
Got a 500GB WD that i just want to buy another one, stick it on and let it work without having to format as the current 500GB is packed of stuff.

WoZZeR · 24 Feb 2007 at 07:55

Haven't a clue, thats a question for the esteemed RPStewart

jellybeard999 · 24 Feb 2007 at 08:40

Yes, you will need to format BOTH drives to create the array, once its created, you can remove a disk, and add a replacement and it will rebuild itself

rpstewart · 24 Feb 2007 at 09:11

tsinc80697 said:
for RAID1 do you have to format both drives?
Got a 500GB WD that i just want to buy another one, stick it on and let it work without having to format as the current 500GB is packed of stuff.

That's a tricky one, it depends on the RAID controller really and it's not something that I'd want to say is possible having never done it myself.

In theory you should be able to:

Create a single disk RAID1 array using the new drive only
Copy the contents of the old drive onto the new one
Add the old drive into the previously created RAID1 array and allow the new drive to mirror onto the old one.

As I say, the ability to do this depends on the controller and a slice of luck. I'd make sure that I had a backup of everything first.

Netvyper · 24 Feb 2007 at 10:02

tsinc80697 said:
for RAID1 do you have to format both drives?
Got a 500GB WD that i just want to buy another one, stick it on and let it work without having to format as the current 500GB is packed of stuff.

As a rule of thumb; yes...

Oddly - I built a RAID1 setup in a shuttle SK22G I think - the new £130 odd ones; And that actually copied the data from 1 disk to the 2nd, and then mirrored it from there onward... it was all a bit wierd

JayMax · 24 Feb 2007 at 10:04

As mentioned - it all depends on the controller. Some controllers will allow online migration/rebuild in the OS from a single disk to raid 0 or 1, and then from 0 or 1 onto 5 etc but rarely backwards.
I'm not sure I can see the benefits of Raid 1 outside of a work/server environment tbh. Any errors will be mirrored and accidental deletions etc.
I need to get this covered myself as currently my 320Gb storage drive has no backup strategy, comparing Raid 1 to an external drive backup plan I think I will go for Acronis and a firewire caddy myself.

tsinc80697 · 24 Feb 2007 at 22:04

oof thats gonna suck if i have to format the 500GB as i dont have anywhere to back all the data up to.

Think it has 300GB of data on it at the moment, might hunt around for a 300GB to back it up on, then format and Raid then transfer the data back on to it, so much hassle!

ste_bla · 24 Feb 2007 at 23:32

tsinc80697 said:
oof thats gonna suck if i have to format the 500GB as i dont have anywhere to back all the data up to.

Think it has 300GB of data on it at the moment, might hunt around for a 300GB to back it up on, then format and Raid then transfer the data back on to it, so much hassle!

OR (my last try i promise

)

1) Buy a 500gb Sata and a Hard Drive Caddy, All you have to do is set up MS Back up or a simple dos command to copy your data onto this drive once a week and then remove drive out of the caddy and store away from the PC. Costs from £19 An example + 1/2 hour setting up MS or Dos

2) Buy a 500gb Sata and a Hard Drive, same back up as above. Costs from £25 An example + 1/2 hour setting up MS or Dos

Also like to point out (in my experience of two motherboard breakages, if your motherboard goes you have to get another with the same raid chip otherwise it wants to format and reload a new Raid partition although that was 3 years ago and it might have changed.

esoteric · 25 Feb 2007 at 11:05

So its essential to have a floppy drive to set up a raid array? I have 2 new HD's coming monday and wanted to raid-0 them, but if I need a floppy drive, which I dont have, I cant do it

rpstewart · 25 Feb 2007 at 11:28

It's not essential to have a floppy to install XP on a RAID array however the XP install will only accept extra drivers from a floppy therefore to install the RAID drivers without a floppy they have to be on the install CD.

That means you need to create a custom install CD using nLite. It's a wizard driven tool which is designed to create bespoke installations for system adminstrators etc and one of its main functions is to integrate drivers into the installation routine so that they don't need to be added later.

esoteric · 26 Feb 2007 at 08:51

So an install of the O/S is required 1st for me to be able to set up a raid without a floppy, great infomation for the future, however ill be putting Vista on these new HD's, so install Vista, use nlite, goto BIOS and setup the raid, in doing so will wipe the hard drives, then install Vista again. Could be a long evening.

After posting the above I realised I only have a DvD-Rom, I dont think ill be able to set up a raid at all, I think a new way for setting up raids needs to be invented

rpstewart · 26 Feb 2007 at 09:00

OK, didn't realise it was Vista you were trying to install. MS have sorted the install process so now you can specify where the drivers are installed from so CDs, USB devices etc are all OK to use.

nLite is XP only btw, I believe there is a vLite on the way for Vista though.

esoteric · 26 Feb 2007 at 09:54

But still, I dont have a media to store drivers on, no CD's, no floppies, no USB sticks, unless I can install from a hard drive, so leave this 1 in with the drivers on, raid my 2 new drives, install Vista etc, then remove the old HD.