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pburt16
11-05-2007, 07:37 AM
Let me state, prior to my question, that I already do regular backups of my data. However, I'm a new convert to SD. So, I don't need a lecture on the value of backups. I'm trying to understand how to set up a fast and safe system that utilizes the power of multiple internal (and/or external) drives.

I have a handle on the basics of RAID 0, 1, & 5. What I can't quite wrap my mind around is how to set up the system. My basic system consists of a Power PC G5 dual HD with an external HD that I have been using for backups. The internal drives are being used as JBOD and don't provide any performance boost.

The big question is: What is the purpose of having an extra internal hard drive (or more) if people generally recommend NOT striping internal drives together as a huge system disk. And, why this is a bad idea, even if you are regularly backing up that disk with a backup drive (for SuperDuper) and/or external Raid 1 array. Is RAID a good idea? What is the purpose of four G5 internal drives on an intel Mac?

I am trying to understand the possibilities and would like to hear from folks who have RAID setups, multiple internal drives, and how to best set up my Mac system.

I'd appreciate any advice,
-p

dnanian
11-05-2007, 09:51 AM
Well... you can certainly concatenate your data as a JBOD, but you could also compartmentalize things a bit. Put music on one large drive, movies on another... or have two drives, each of which is a mirrored raid of two...

Personally, I avoid striping, even with a good backup. But that's me.

NoNameBRand
11-06-2007, 01:44 PM
The big question is: What is the purpose of having an extra internal hard drive (or more) if people generally recommend NOT striping internal drives together as a huge system disk. And, why this is a bad idea, even if you are regularly backing up that disk with a backup drive (for SuperDuper) and/or external Raid 1 array. Is RAID a good idea? What is the purpose of four G5 internal drives on an intel Mac?

Firstly, "RAID0" isn't RAID - that "R" stands for redundant, and a stripped array of N disks is N times more likely to fail than one disk.

However, If you have good backups, there's no compelling reason not to use a striped array for a boot volume. It'll certainly be fast.


I use my second internal drive as a clone of the first (two partitions on each, one for my System + Users and the other for my photographs) - it's just more convenient to me to have my hot backup inside the box. I'd considered mirroring them (RAID1), but a nightly clone is good enough for availability and being able to selectively backup prior to updates and immediately rolling back from failed updates is wonderful.

I have two external disks in an eSATA enclosure, and use partitions on them for: music, movies, games, backup of other computers at my place and now Time Machine; all stuff I don't need backed up.

I've taken a small partition off each of my four disks (~8 GB each), and used them to create a four disk striped array for Photoshop scratch use, which is the only thing I do that needs a super fast volume, and it really, really helps. If I did video work, I would make a much larger striped volume and use it as the work disk.

LarMatre
11-06-2007, 06:26 PM
What is the purpose of four G5 internal drives on an intel Mac?

My 2¢ ... My primary workstation is a G5 DualCore. It has but two internal drive bays, with only one empty. I have the original 250GB drive and added a 1TB. I wish I had four. Why?...

1) Speed. SATA is (I believe) at least 2.5 times faster than FireWire 800.
2) Clean and uncluttered desk, free of external drives.
3) Drive choice. I buy Seagate. They come with a five-year warranty. I've nailed external drive makers in the past who said my drive was out of warranty (their warranty of one year) yet I pointed out to them the drive had a three year warranty. They would have charged me for a new drive, but I made noise and got it for free under the drive's warranty.

LarMatre
11-06-2007, 06:34 PM
Personally, I avoid striping, even with a good backup. But that's me.

Dealing with a RAID is risky, I know from experience. So routine backups are essential. But, one really needs a reason to want to set up a RAID ... in your work, would you ever need a RAID, either 0 or 1?

I work on Photoshop files that have grown to 1.7GB ... that's when I wasn't paying attention. But they are often up in the 800MB to 1.2GB range, and there's nothing I can do about those.

I also do video editing. If I didn't need to take the risk with RAIDs, I wouldn't. But it makes a big performance difference for me.

pburt16
11-07-2007, 09:25 AM
I appreciate all the advice. My primary reason for exploring Raid options is performance. I am regularly dealing with massive Photoshop and video files.

I think, based on the suggestions, I may wait to implement a Raid solution after I have the means to upgrade to a 4 drive Intel system.

I've invested a lot of money in external drives and don't want to reformat my main hard drives at this time.