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View Full Version : I know nothing about RAID.....


Little Endian
Feb 17, 2005, 09:37 PM
I know virtually nothing about setting up a RAID array and need help on deciding whether to use RAID 0 or 1. I know that RAID 0 offers much better performance over RAID 1 hower does RAID 1 still offer any speed improvement over using just one drive? How reliable and safe is a RAID 0 setup? I currently have one Drive which is my boot drive would I have to do a reformat and reinstall of that drive if I were to add a second and create a RAID 0 array? How important is using the same model drives in a raid Array? Thanks in advance.

Hoef
Feb 17, 2005, 10:04 PM
What is your primary objective.....? If reliability is very important, never do raid 0 as it is less reliable than a single HD (HDs are pretty reliable these days!). If you are after speed, do the raid 0 thing, raid 1 wouldn't help there (besides you have only half the space of the two HDs).

Why do you want to do raid again?

daveL
Feb 17, 2005, 10:09 PM
Google: RAID. Or search the MR forums. This topic has been addressed a dozen times over.

topher
Feb 17, 2005, 10:14 PM
Without professing to know much beyond RAID 0 and 1, I think I can clarify somewhat.

RAID type 0 is also known as striping. It basically interleaves the format of the hard drives so that sequential pieces of data are written alternately to each of the drives in the RAID. The only reason to use this setup is to eliminate the bottleneck that occurs when all of that data gets in one line to be written to the drive. It offers performance enhancements, but no redundancy...so if any of the drives in your array fails, you will lose all data.

RAID 1 essentially employs a built in redundant drive. All data is written, and then rewritten to the second drive. Since there are two drives with identical data, they can be read simultaneously. So, it helps some when you are reading, but doesn't offer any extra performance when writing. But, since everything is at least once redundant, it is more fail-safe.

I'm almost certain that you would have to reformat the drive you currently own for a RAID 0, because the drives have to be paired and interleaved. I don't know if having drives of the same make and model is necessary, but because the purpose of any RAID is to fine tune performance, and/or fault tolerance, it seems like having matching drives would be wise.

Two last things.
1) This might help: http://www.acnc.com/04_01_00.html
2) I think from what I have read, that the magnitude of bottlenecking that has to happen before a RAID 0 would provide meaningful performance enhancements is hard to acheive in day to day life. You might be wasting time and effort to eek out a slight increase in speed. And if you're shooting for RAID 1, an external drive for backups might be easier.

cyanide
Feb 17, 2005, 10:26 PM
a RAID array can easily be setup to thwart the evil plans of even the most villainous cockroaches. Simple begin by placing RAID hotels and spray at the perimeter of intervals of 20 feet and then... oh sheesh.. i did it again. this isn't the pest control rumors forum is it? I need sleep..

pulsewidth947
Feb 18, 2005, 08:05 AM
I use RAID 1 on my PC, so i've always got an instant backup. It also makes xp load slightly quicker, although that might just be me thinking it is faster :D

I reckon its worth doing nowadays as you roughly get 2 gb per 1 in UK, so i got 2 Maxtor 120GB SATA drives for 110..

RAID was really easy to set up on the PC, so it must be even easier on a Mac!

Brize
Feb 18, 2005, 08:31 AM
I use RAID 1 on my PC, so i've always got an instant backup.

Given that the two drives are mirrored, how reliable is it to use RAID 1 as a backup solution? I guess it would be useful in the case of physical drive failure, but in the case of file corruption or accidental deletion, you'd surely lose the data on both drives, no?

varmit
Feb 18, 2005, 09:17 AM
http://raid.com/04_00.html

You can use the link to find out what each raid is, and what its advantages and disadvantages are for that particular raid setup.

Lacero
Feb 18, 2005, 09:18 AM
Good link there Varmit

pigbat
Feb 18, 2005, 09:48 AM
Given that the two drives are mirrored, how reliable is it to use RAID 1 as a backup solution? I guess it would be useful in the case of physical drive failure, but in the case of file corruption or accidental deletion, you'd surely lose the data on both drives, no?

You are correct. With RAID 1 you are backed up from a hardware failure, not a user created failure.