Apple RAID Card and 3TB Drives only show 2.2 TB

Question

Apple RAID Card and 3TB Drives only show 2.2 TB

I tried a 3TB Seagate Barracuda XT drive in the July 2010 Mac Pro (and a Jan 2008 Mac Pro) on the RAID Card that came with the machines (so one is the RAID Card now shipping) and both show a maximum of 2.2 TB with a 3TB drive.

I'm curious if anyone else has tried this with different results. Any luck in getting the RAID Card to see the full 3TB in the drives?

By the way, without the RAID Card, the Mac (OS 10.6.4) sees the full 3TB, but not with it.

Anyone else seeing this?

2010 Mac Pro, Mac OS X (10.6.4)

Posted on Sep 14, 2010 12:37 PM

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Answer 1

Sep 14, 2010 12:41 PM in response to Christian Riley

p.s. I think this should have gone in the post-2009 section, but it applies to both 2008 and 2010 Mac Pros and couldn't figure out how to move it.

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Answer 2

The hatter

Level 9

61,041 points

Sep 14, 2010 1:58 PM in response to Christian Riley

You didn't read the FAQ for the card, it is normally overhead.
Assumes you are using RAID3/5 and not mirror or stripe of course.

http://www.apple.com/support/macpro

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Answer 3

Nov 12, 2010 3:26 PM in response to The hatter

I definitely read the FAQ, this is a completely different issue as described.

With the RAID Utility each drive shows only 2.2TB not 3.0TB. A 2 TB drive shows 2.0TB in the RAID Utility. A 1 TB drive shows 1.0TB in the RAID Utility.

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Answer 4

The hatter

Level 9

61,041 points

Nov 12, 2010 4:28 PM in response to Christian Riley

Okay. Seems Apple didn't plan for or certify 3TB.

However, Apple doesn't support using 3rd party drives. Some do, and in some situations, drives you would think work don't, or they work but only briefly.

When I said read FAQ I was thinking of all the points like this:

Question: *Which drives does Apple support for the Mac Pro RAID Card and the Xserve RAID Card?*

Answer: Only Apple SATA drives and Promise 450GB SAS Drive modules sold through the Apple Store are supported for use with the Mac Pro RAID Card (Early 2009) and the Xserve RAID Card (Early 2009).

Apple 300GB SAS Drive modules are supported with the Mac Pro RAID Card (Late 2007) and Xserve RAID Card (Early 2007).

Drives must be either all Serial ATA (SATA) or all Serial Attached SCSI (SAS) drives. SSD drive modules are not recommended for the Apple RAID Card because these drives use their own on-disk cache and cannot take advantage of the protection provided by the battery-backed cache on the RAID card.

http://support.apple.com/kb/HT1346#faq8

http://www.apple.com/support/macpro/

Apple Knowledge Base: recent changes:
http://support.apple.com/kb/index?page=articles

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