Raid---How does it work

bothanspy · 05-01-04, 04:01 AM

Quote:

Looks good to me. I'd have gone for a different case but thats just asthetics. Hopefully you have 2 hard drives that you can raid 0 and get some screamin performance from them. Don't forget to grab the raid driver from ASUS website if you do do that for the XP setup...that first part where it says press f6 to install 3rd paty raid.

SilverSurfer posted this before. How does Raid work? Do I have to have exactly the same hard drive, or the same size, or the same manufacturer, or a combination of the above?

SPY

Trigger · 05-01-04, 07:46 AM

AFAIK, you have to have 2 of the same drive, I never tried setting it up with two drives with different mfgrs, but same size - doubt it would work...

Basically - it works by making one large volume out of the two drives and alternating which one it writes data to so that it speeds up the read/write access. I don't like RAID because if one drive has a physical failure, you pretty much lose the data on both drives. It happened to me with a machine I bought from Alienware. If you want really fast performance, you can check out the 10000rpm ata drives available - last I saw they had 74gb versions.

TheMadMonk · 05-01-04, 08:34 AM

See buy. Spray bug. Raid kills bugs dead!

X · 05-01-04, 09:12 AM

IDE RAID 0 generally works with different size drives from different manufacturers, but I wouldn't recommend it.

You will only get the capacity of 2x the smallest drive and performance will be held back somewhat if one drive is slower than the other or if their timing characteristics are different.

RAID 0 stripes the data across the two drives which means they read and write data in parallel and both are needed to recover the data. Therefore if one drive goes out the other is useless data-wise. With two drives there is a higher chance of something going wrong than with one drive.

RAID 0 may not give much of a performance boost at all on the normal consumer IDE motherboard. I've seen figures showing it's faster and ones showing it's slower. It's probably not worth the cost.

You must have a good backup method if you use RAID 0. I do and I have two 10K RPM Raptor drives in a RAID 0 configuration. It's fast, and faster than my other decent drives, but the Raptor is very fast all by itself. If I had one of the drives go out on me I would probably convert to RAID 1 (mirrored drives) when I rebuilt the array.

LolaRennt · 05-01-04, 01:57 PM

There are various different RAID levels. Each has advantages and disadvantages.

Short summary:
RAID0 gives you generally the highest performance, but no security: if one drive goes down, you lose all your data

RAID1 gives you a lower performance than a single drive, but excellent redundancy. Basically all data is copied to 2 drives, so if one of those drives goes down, you don't lose a shred of data

RAID5 gives good read performance, but poor write performance. Excellent for read-intensive applications. It also offers a good level of security: any single drive in the array can go down, and you don't lose any data. If 2 drives go down at the same moment, you lose everything...

johnglass · 05-01-04, 02:44 PM

Quote:

Originally posted by LolaRennt
There are various different RAID levels. Each has advantages and disadvantages.

Short summary:
RAID0 gives you generally the highest performance, but no security: if one drive goes down, you lose all your data

RAID1 gives you a lower performance than a single drive, but excellent redundancy. Basically all data is copied to 2 drives, so if one of those drives goes down, you don't lose a shred of data

RAID5 gives good read performance, but poor write performance. Excellent for read-intensive applications. It also offers a good level of security: any single drive in the array can go down, and you don't lose any data. If 2 drives go down at the same moment, you lose everything...

I think I would replace 'security' with 'redundancy', but other than that

X · 05-01-04, 03:10 PM

And I don't think I'd say RAID 1 is lower performance. It may be a bit slower on writes but it's faster on reads.

jrobinson · 05-01-04, 03:14 PM

Quote:

Originally posted by johnglass
I think I would replace 'security' with 'redundancy', but other than that

I think I'd replace the word redundancy with fault tolerance

johnglass · 05-01-04, 06:17 PM

Quote:

Originally posted by jrobinson
I think I'd replace the word redundancy with fault tolerance

You're being redundant.

Trigger · 05-01-04, 07:07 PM

I think I'd replace fault tolerance with ice cream

05-01-04, 07:46 AM	#2
Trigger DVD Talk Legend Join Date: Jul 2000 Location: Arizona, USA Posts: 23,458	AFAIK, you have to have 2 of the same drive, I never tried setting it up with two drives with different mfgrs, but same size - doubt it would work... Basically - it works by making one large volume out of the two drives and alternating which one it writes data to so that it speeds up the read/write access. I don't like RAID because if one drive has a physical failure, you pretty much lose the data on both drives. It happened to me with a machine I bought from Alienware. If you want really fast performance, you can check out the 10000rpm ata drives available - last I saw they had 74gb versions. __________________ theomnom.com Before you speak, ask yourself, is it kind, is it necessary, is it true, does it improve on the silence? Sai Baba

05-01-04, 01:57 PM	#5
LolaRennt Senior Member Join Date: Mar 2003 Posts: 758	There are various different RAID levels. Each has advantages and disadvantages. Short summary: RAID0 gives you generally the highest performance, but no security: if one drive goes down, you lose all your data RAID1 gives you a lower performance than a single drive, but excellent redundancy. Basically all data is copied to 2 drives, so if one of those drives goes down, you don't lose a shred of data RAID5 gives good read performance, but poor write performance. Excellent for read-intensive applications. It also offers a good level of security: any single drive in the array can go down, and you don't lose any data. If 2 drives go down at the same moment, you lose everything... __________________ Der Ball ist rund.

05-01-04, 07:07 PM	#10
Trigger DVD Talk Legend Join Date: Jul 2000 Location: Arizona, USA Posts: 23,458	I think I'd replace fault tolerance with ice cream __________________ theomnom.com Before you speak, ask yourself, is it kind, is it necessary, is it true, does it improve on the silence? Sai Baba

05-01-04, 08:34 AM	#3
TheMadMonk DVD Talk Platinum Edition Join Date: Feb 2001 Posts: 3,171	See buy. Spray bug. Raid kills bugs dead!

05-01-04, 09:12 AM	#4
X Administrator Join Date: Oct 1987 Location: AA- Posts: 10,144	IDE RAID 0 generally works with different size drives from different manufacturers, but I wouldn't recommend it. You will only get the capacity of 2x the smallest drive and performance will be held back somewhat if one drive is slower than the other or if their timing characteristics are different. RAID 0 stripes the data across the two drives which means they read and write data in parallel and both are needed to recover the data. Therefore if one drive goes out the other is useless data-wise. With two drives there is a higher chance of something going wrong than with one drive. RAID 0 may not give much of a performance boost at all on the normal consumer IDE motherboard. I've seen figures showing it's faster and ones showing it's slower. It's probably not worth the cost. You must have a good backup method if you use RAID 0. I do and I have two 10K RPM Raptor drives in a RAID 0 configuration. It's fast, and faster than my other decent drives, but the Raptor is very fast all by itself. If I had one of the drives go out on me I would probably convert to RAID 1 (mirrored drives) when I rebuilt the array.

05-01-04, 03:10 PM	#7
X Administrator Join Date: Oct 1987 Location: AA- Posts: 10,144	And I don't think I'd say RAID 1 is lower performance. It may be a bit slower on writes but it's faster on reads.