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Multiple drives and RAID card

R

Rokeneer

macrumors regular
Original poster
Sep 27, 2011
119
0
Hi!

I have a Mac Pro (first edition) quad-core (2x 3GHz dual core Xeon) and I am wondering if I need a RAID card for my purposes.

I'd like to have 2 hard drives for storage (the 250gig stock plus another larger drive), a third drive for time machine, and a fourth drive strictly as a windows drive (no backup needed).

Do I need to have the actual RAID card, or can I just use the RAID software for my purposes?

Thanks for the help!
 
You don't need a RAID card for four internal drives, and furthermore, you don't need to RAID any of your drives given what you want to do.

You have four slots, and currently one 250GB drive, right? If you added say 3 more 2TB drives, for example, you could RAID the 2TB drives together into RAID0 or RAID1, but why? You'd be better served just leaving all four drives individual, and using #1 (250GB) for OSX, #2 for data, #3 for Time Machine and #4 for Windows. This can all be done via software RAID built into Disk Utility.

Note that if you RAID a larger drive to the 250GB drive, it will result in the larger one being seen as only 250GB as well. Wasteful. RAID drives are supposed to be the same size so that they can act as a mirror or stripe across all disks equally.

If you're willing to do a little shuffling and cloning, you'd really benefit from getting three new large disks, and cloning your current disk to one of the new larger ones. Then, format the 250GB disk and do a clean install of Windows on it, using that one for Windows obviously. Then you could RAID the two other disks for data, either fast RAID0 or mirrored RAID1. Either that, or just skip the RAID idea and use the two remaining for Time Machine and extra data.
 
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Ok. Thanks!

Yes, one of my slots has the 250 with three slots empty.
In the case you described, would time machine back up both the OSX drive AND the data drive, or just one of the 2?
 
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wonderspark said:
Note that if you RAID a larger drive to the 250GB drive, it will result in the larger one being seen as only 250GB as well. Wasteful. RAID drives are supposed to be the same size so that they can act as a mirror or stripe across all disks equally.
Click to expand...
Some may be willing to live with the loss in capacity when using mixed drives, such as those using existing drives in order to save money up front.

But as a general rule, it's best to keep the size of each disk ~ the same. ;)
 
wonderspark said:
You'd be better served just leaving all four drives individual, and using #1 (250GB) for OSX, #2 for data, #3 for Time Machine and #4 for Windows. This can all be done via software RAID built into Disk Utility.
Click to expand...

So in this situation, would time machine (disk 3) be able to back up both the software drive (disk 1) and the data drive (disk 2), or only one of the two?
 
Rokeneer said:
So in this situation, would time machine (disk 3) be able to back up both the software drive (disk 1) and the data drive (disk 2), or only one of the two?
Click to expand...

It will automatically back up all local drives, unless you specify which ones not to back up. Likewise, you can specify folders inside drives not to back up as well. This is done via the exclusion list. So you might want to back up just OSX and Windows, or just OSX and the data disk, or all three except one folder on one of them, and so on.
 
wonderspark said:
It will automatically back up all local drives, unless you specify which ones not to back up. Likewise, you can specify folders inside drives not to back up as well. This is done via the exclusion list. So you might want to back up just OSX and Windows, or just OSX and the data disk, or all three except one folder on one of them, and so on.
Click to expand...


Thanks! That helps for everything but one last question.

How do I get to said exclusion list?
 
wonderspark said:
http://support.apple.com/kb/HT1427

When you open your System Preferences and click on the Time Machine icon, you'll see a button called Options. When you click it, it pulls up another window that has drives to exclude, with +/- buttons to add or remove them.
Click to expand...


Ok thanks! That answers all my drive questions.

Instead of starting a new thread, I'll just ask my other question here.

I would like to use my Mac Pro as a DVR to record tv, and would like to do it using a PCI Express tuner/capture card. Does anybody know of any good tuner/capture cards out there that would work with my first generation Mac Pro (OS 10.6.8)? Also, what software would I need to record it? I have adobe master collection CS5 as well as final cut express (not sure what version)
 
wonderspark said:
You have four slots, and currently one 250GB drive, right? If you added say 3 more 2TB drives, for example, you could RAID the 2TB drives together into RAID0 or RAID1, but why? You'd be better served just leaving all four drives individual, and using #1 (250GB) for OSX, #2 for data, #3 for Time Machine and #4 for Windows. This can all be done via software RAID built into Disk Utility.
Click to expand...

So i got the disks I wanted, 2x 250gb, 2tb, 3tb. My question now is, how do I set up said RAID using the Software? I have no understanding of what is showing up in disk utility and really need some help. Also, my primary drive has the SMART Status "failing", but when I ran "verify disk" is said it appears to be ok. About how long will it last before I need to replace it?
 
Rokeneer said:
So i got the disks I wanted, 2x 250gb, 2tb, 3tb. My question now is, how do I set up said RAID using the Software? I have no understanding of what is showing up in disk utility and really need some help. Also, my primary drive has the SMART Status "failing", but when I ran "verify disk" is said it appears to be ok. About how long will it last before I need to replace it?
Click to expand...
By primary disk, you mean the main disk with OSX on it?

To RAID:
- In Disk Utility, click RAID button (between Erase and Restore buttons, top right)
- Give it a name by RAID Set Name, format as Mac OS Extended (not journaled)
- Choose Striped for RAID0 or Mirrored for RAID1.

Drag the two identical disks into the box below that from the panel with all disks shown on the left, and click Create at the bottom.
 
wonderspark said:
By primary disk, you mean the main disk with OSX on it?

To RAID:
- In Disk Utility, click RAID button (between Erase and Restore buttons, top right)
- Give it a name by RAID Set Name, format as Mac OS Extended (not journaled)
- Choose Striped for RAID0 or Mirrored for RAID1.

Drag the two identical disks into the box below that from the panel with all disks shown on the left, and click Create at the bottom.
Click to expand...

Yes, the drive that has osx on it. Also, isn't the setup Described for 1 as os, 2 for data, and 3 for time machine a jbod setup? If so, wouldn't that be the third option in the menu?

Here's how I want it set up:
1: 250gb os/applications
2: 2tb data
3: 3tb time machine
4: 250gb windows
 
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Rokeneer said:
Yes, the drive that has osx on it. Also, isn't the setup Described for 1 as os, 2 for data, and 3 for time machine a jbod setup? If so, wouldn't that be the third option in the menu?

Here's how I want it set up:
1: 250gb os/applications
2: 2tb data
3: 3tb time machine
4: 250gb windows
Click to expand...
Ah, I see now.
With only four disks being used for four different purposes, you won't be using a RAID as you've laid it out, so no need to make a RAID at all. Just use the four drives separately as you've described.

The point of RAID is to either increase speed, increase redundancy or both. If you need greater disk read/write throughput, you'd want to stripe disks in a RAID so that the data is being written to multiple disks at the same time. A set of two disks that have a throughput of 130MB/second will write at about 260MB/second if striped together in RAID0.

On the other hand, say you need redundancy, so you mirror two disks together in RAID1. Now it writes to both disks at the same time, but at 130MB/second onto two separate disks. One fails, no problem because you have the other one that is a 'mirror' of the first. You replace the bad one and it rebuilds the mirror from the good disk.

You have four separate needs and four disks, so it doesn't make any sense to build a RAID. If you had a fifth disk, say an external 3TB disk for Time Machine, then you could RAID the two identical 250GB disks together for faster speed or data redundancy. On that note, I don't advise making a stripe (RAID0) of the OS and programs unless you have a clone of that drive elsewhere, because if one fails, you have no system disk, and that's a major hassle. This is in case you were thinking of making a RAID0 of the two 250GB disks as a 500GB volume, and then partitioning it. Don't do that.
 
wonderspark said:
Use that for what's least important for you until you get a replacement for it. If it's a brand new drive, have the manufacturer replace it under warranty.
Click to expand...

It's the original drive that shipped with the computer. I think I'll use it until it dies, and then boot from time machine until I can get a new drive.
 
Rokeneer said:
It's the original drive that shipped with the computer. I think I'll use it until it dies, and then boot from time machine until I can get a new drive.
Click to expand...
I don't think you can boot from Time Machine. You'd need an actual clone to boot from if that drive dies.
 
To copy the data from the dying disk to a new disk, I would put the new drive into one of the drive slots, set up a RAID1, let it copy the data, replace the dying drive with the good one, and throw the bad one on a shelf. Am I correct?
 
You really should pick up either Carbon Copy Cloner (CCC) or SuperDuper! which is what I have. I forgot why I chose that over CCC, which I think is more popular, but either one is the ideal way to clone a disk.
 
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