Mac Pro Raid Card

The RAID card is needed only for RAID-5. RAID-0 can be created with Disk Utility, and does not need the card.

I have been told that when I install my new RAID card in my 8-core MacPro, I can set it up as RAID 1 without reformatting the two drives, but can I set up the two drives as RAID 0 without reformatting?

Thanks

I can set it up as RAID 1 without reformatting the two drives, but can I set up the two drives as RAID 0 without reformatting?

Using Disk Utility you will need to reformat both a new RAID 1 or a RAID 0.

Yes, with the RAID card and RAID Utility, you can indeed prepare a mirror without having to erase because the card controls how the drives are used whereas with Disk Utility the RAID setup has to be written onto the drives themselves meaning they kind of have to be 'started from scratch'.

I am not aware of being able to stripe without erasing with the RAID Utility and RAID card.

Isn't the software raid 0 performance less than a hardware Raid 0?

Slightly, but it is unlikely you would notice it for RAID-0. There would be a huge difference for RAID-5, if you can even find a software version.

So here's a question from an almost complete novice on all this: If I can RAID the three other 500Gb drives in my MP simply using disk utility, can I make a RAID 1 using that RAID and an external 1Tb drive? Can you RAID a RAID? Or would it just need to be a Time Machine b/u of that internal RAID?

And incidentally, what's the point of buying a RAID card for a RAID 0 or 1? I bought this 2007 MP used with the Apple RAID card in it and those three drives set up as a RAID 0. Why was the card necessary?

Like I said, I'm brand new to all this, so be gentle.

So here's a question from an almost complete novice on all this: If I can RAID the three other 500Gb drives in my MP simply using disk utility, can I make a RAID 1 using that RAID and an external 1Tb drive? Can you RAID a RAID? Or would it just need to be a Time Machine b/u of that internal RAID?

Even if Disk Utility allowed this, I wouldn't try it. RAID 1 volumes must be equal sizes, so it would only be able to use 1 TB of your three 500 GB drives, in order to match the 1 TB external drive. Also, write speeds would be limited by the single external drive.

And incidentally, what's the point of buying a RAID card for a RAID 0 or 1?

The cache on the card might provide a slight speed-up, but probable not noticeably. Unlike with software RAID, it is possible to install firmware updates while booted from a hardware RAID set. The RAID card will allow the use of SAS drives. Unless you need RAID 5, or SAS drives, there is no reason to buy the RAID card.

I bought this 2007 MP used with the Apple RAID card in it and those three drives set up as a RAID 0. Why was the card necessary?

It wasn't, unless the previous onwer was thinking of RAID 5. You can remove the card if you want to, and regain deep sleep capability. Just read the card installation manual backwards. Make sure you have good backups, since you will probably lose all the data when setting up software RAID.
<http://manuals.info.apple.com/en US/MacPro_RAIDCardInstallation.pdf>

Malcolm Rayfield, you rock. Thanks greatly for the installation manual. I've been looking for something like that and hadn't found it yet. Important question: Does it apply to the new Nehalem MPs as well?

And a follow-up: What problems will I run into, if any, when I do upgrade--I do want the SAS functionality eventually--to an actual RAID card?

Will I need to format the drives that are software-RAIDed and re-install from the backup to the hardware-RAID?

Tanks a million.

C.

Thanks greatly for the installation manual. I've been looking for something like that and hadn't found it yet. Important question: Does it apply to the new Nehalem MPs as well?

Probably not. The new Mac Pro mentions "the new Mac Pro RAID Card" and "A new cableless connection" in its RAID description
<http://www.apple.com/macpro/features/storage.html>

And a follow-up: What problems will I run into, if any, when I do upgrade--I do want the SAS functionality eventually--to an actual RAID card?

Current SAS drives give very little performance advantage over the Velociraptor drives.

Will I need to format the drives that are software-RAIDed and re-install from the backup to the hardware-RAID?

Probably. The Mac hardware and software RAID might be compatible, but I wouldn't count on it. Even minor changes, such as updating a drive's firmware, can break a RAID set. Here is the manual for the RAID card
<http://manuals.info.apple.com/en US/RAID_Utility_UserGuide.pdf>

The only reason there's been any complaints about the new RAID Card is becasue it's not released. How can anyone complain about something's functionality, when there's nothing to test or physically complain about?

I set mine up using a software RAID, until the new Card comes out (w/a boot, 2 x media RAID 0, and an export). Also, there will be third party offerings, once the other companies can see how Apple is addressing the drives from the card (CalDigit, Sonnet, Atto, etc.). I'm just keeping a handy eSATA drive (eSATA cards work in the new Mac Pros) for backup dump-off, when I have to re-format the drives, once the card actually comes in.

The delay is correct, as they're finalizing testing / functionality of the new cards. It's worth the wait, as these cards will be faster than they've ever been on a Mac.