Mac Pro Drive Config

[jakesaunders27]

Hi,
Want to put 2 3TB WD Caviar Black or Red in my Mac Pro and configure then in a RAID 0 formation. Obviously this will give me speed but I'm wondering if I'm better of just having the two hard drives in with no RAID whatsoever. As I would want to partition the RAID so half is one volume for my projects and second volume for my sample library. So this would make it 3TB per volume, but as the drives are 3TB drives am I better of just having the drives separate or will it still be faster to do RAID 0. Hope you can get what I mean!

Jake

 

[jakesaunders27]

Also just found out I have a RAID controller installed, I thought it was just an eSATA card? Doesn't look like the proper Apple one, can I use this instead of software?

Cheers

Jake

 

[jakesaunders27]

Anyone?

 

[slughead]

First off, how did you not know you had a RAID card installed?

Second, we'd have to know what kind of card that is before being able to tell you anything with 100% certainty (you need to look in your case). In general though, RAID cards don't offer much advantage over the built-in controller for platter drives, even when running a RAID. This is because most RAID cards are actually just software RAID run through a proprietary controller.

The advantages of software RAID through Apple's Disk Utility are quite clear: Robust software and your drives will work with any controller. You can take your drives out of your Mac Pro, throw them in a Firewire/USB/Thunderbolt enclosure, and your array will mount and work just fine. You cannot do this if you use a RAID card to build your array.

As far as JBOD vs RAID: RAID0 is going to give you significantly increased performance over having loose drives, even if you have them separate. Unfortunately, it also massively increases your risk of losing all your data. If any drive in a RAID 0 fails, you lose 100% of your data. Compare that to having half your data on one drive, and half on the other: If one drive fails, you loose 50% of your data.

Since you're using 3TB drives--which have a higher failure rate than say, 1TB drives--you're really going to need a backup solution in EITHER case.

If you need that much storage, I would recommend buying FOUR hard drives and making a RAID 10 or 01 out of it using Apple's software RAID. This is basically a RAID 0 being "mirrored" (backed up) in real time by another RAID 0 (or a RAID 1 striped with another RAID 1). If 1 drive fails or, sometimes, if 2 drives fail, you will still have all your data. You can continue to use your array at full speed until replacement drives arrive in the mail.

That would give you fast performance as well as data security. It obviously doubles the price, but how much is your data really worth?

I have a huge amount of hard drives hooked to my Mac Pro (13?). I have lost tons of drives over the years through failures. If you're not backing up, you're almost assured to lose some of your data some day.

 

[jakesaunders27]

First off, how did you not know you had a RAID card installed?

Second, we'd have to know what kind of card that is before being able to tell you anything with 100% certainty (you need to look in your case). In general though, RAID cards don't offer much advantage over the built-in controller for platter drives, even when running a RAID. This is because most RAID cards are actually just software RAID run through a proprietary controller.

The advantages of software RAID through Apple's Disk Utility are quite clear: Robust software and your drives will work with any controller. You can take your drives out of your Mac Pro, throw them in a Firewire/USB/Thunderbolt enclosure, and your array will mount and work just fine. You cannot do this if you use a RAID card to build your array.

As far as JBOD vs RAID: RAID0 is going to give you significantly increased performance over having loose drives, even if you have them separate. Unfortunately, it also massively increases your risk of losing all your data.

Since you're using 3TB drives--which have a higher failure rate than say, 1TB drives--you're really going to need a backup solution in EITHER case.

If you need that much storage, I would recommend buying FOUR hard drives and making a RAID 10 out of it using Apple's software RAID. That would give you fast performance as well as data security. It obviously doubles the price, but how much is your data really worth?

I have a huge amount of hard drives hooked to my Mac Pro (13?). I have lost tons of drives over the years through failures. If you're not backing up, you're almost assured to lose some of your data some day.

Thanks a lot, I bought it second hand a while ago so I didn't know. I have since found out its a Sonnet Tempo E2P

http://www.sonnettech.com/product/tempo_sata_e2p.html

From what i've looked at I think its literally just a eSATA card (which is what I thought when I got it), secondly how come RAID 0 gives and increase on loosing data is it because it is spread out across the drives? And i currently have a 1TB RAID 1 configuration backed up by an external hard drive every hour however I'm running out of space because of all the projects I create (I'm using Logic, Pro Tools etc). I also want to change my SSD as i'm running out of room on that so that takes up one bay so I'm not really too sure of the best solution, what would you do?

Cheers

 

[slughead]

Thanks a lot, I bought it second hand a while ago so I didn't know. I have since found out its a Sonnet Tempo E2P

http://www.sonnettech.com/product/tempo_sata_e2p.html

From what i've looked at I think its literally just a eSATA card (which is what I thought when I got it), secondly how come RAID 0 gives and increase on loosing data is it because it is spread out across the drives? And i currently have a 1TB RAID 1 configuration backed up by an external hard drive every hour however I'm running out of space because of all the projects I create (I'm using Logic, Pro Tools etc). I also want to change my SSD as i'm running out of room on that so that takes up one bay so I'm not really too sure of the best solution, what would you do?

Cheers

RAID 0 is more likely to lose data just because you're using 2+ drives functioning as one. If either/any fail, you lose all your data. It's not something special about the RAID that makes them fail, it's just the fact that the fate of your data is tied to the health of 2 drives instead of one. The chance of one drive failing is "X", the chance of either of 2 drives failing is "2 * X".

Take this example of a RAID 0. What happens if one drive fails? You have only half the data, which makes the other half useless. Effectively you lose everything:

 

[jakesaunders27]

RAID 0 is more likely to lose data just because you're using 2+ drives functioning as one. If either/any fail, you lose all your data. It's not something special about the RAID that makes them fail, it's just the fact that the fate of your data is tied to the health of 2 drives instead of one. The chance of one drive failing is "X", the chance of either of 2 drives failing is "2 * X".

Take this example of a RAID 0. What happens if one drive fails? You have only half the data, which makes the other half useless. Effectively you lose everything:

Image

I see thanks for that picture thats cleared things up a bit! What have you got in your mac pro and externally? (hard drive wise)

Cheers

 

[slughead]

I see thanks for that picture thats cleared things up a bit! What have you got in your mac pro and externally? (hard drive wise)

Cheers

I use a card similar to what you have (the eSATA card) and I use it to run an external array I built myself (pictures here) which has two port multipliers. There is a RAID 10 and a RAID 1 in there. I also run a time machine on a 3TB drive backing up a 1TB drive and a 2TB RAID 0 (inside the MP). I boot off a SSD.

It's been working for years. In spite of multiple drive failures I've never lost any data.

 

[jakesaunders27]

I use a card similar to what you have (the eSATA card) and I use it to run an external array I built myself (pictures here) which has two port multipliers. There is a RAID 10 and a RAID 1 in there. I also run a time machine on a 3TB drive backing up a 1TB drive and a 2TB RAID 0 (inside the MP). I boot off a SSD.

It's been working for years. In spite of multiple drive failures I've never lost any data.

Wow that looks brilliant, I have a few bits lying around from my PC before my Mac Pro, might look at utilising that! Thats such a big help mate I appreciate it.

 

[slughead]

Wow that looks brilliant, I have a few bits lying around from my PC before my Mac Pro, might look at utilising that! Thats such a big help mate I appreciate it.

For larger arrays you save a ton of money doing that. Just don't skimp on the power supply!

 

[jakesaunders27]

For larger arrays you save a ton of money doing that. Just don't skimp on the power supply!

I can imagine thats not the best thing to skimp on!