I recently built a five-drive, RAID 5 server using a Sans Digital MobileRaid and five 1TB drives with the intent of connecting them to my Mac Mini over USB (Speed is a low priority). However, I’ve come to learn that bot Firewire and USB are both limited to recognizing a maximum of 2TB. Is there any way around this?
Where, exactly did you learn this?
Firewire is a transport medium - AFAIK, it doesn’t care about drive sizes.
And, BTW, USB sux - use Firewire.
There may be OS volume size limitations.
Correct me if I’m wrong, but won’t your RAID 5 enclosure look like a 1TB drive to the Mac?
Quote: Correct me if I’m wrong, but won’t your RAID 5 enclosure look like a 1TB drive to the Mac?
Raid5 splits the data and creates additional parity information that is then striped to all available drives (RAID - Wikipedia). So with 5x 1TB drives the capacity of one is lost to parity giving a total usable capacity of 4TB.
Link in the OP says: The MobileRAID MR5CT1 Series is an external compact RAID solution designed for file servers, video editing, and data storage. With up to 5TB of total storage capacity (64 bit OS, MAC OS 10.4 or above, Windows 64 bit Editions and LINUX 64 bit, supports over 2TB in one volume, 32 bit OS has max. 2TB per volume limitiation).
So you’ll need a 64bit OS to use the full 4TB, operating system limitation rather than USB or Firewire limits.
Currently, it looks like a 2TB drive to my mac, but the admin panel shows it to be a 4TB drive.
I’m running Mac OS X 10.5.5.
Per beowulff’s note it’s an OS issue for Mac 32 bit OSes, nothing to do with the drive or the IO medium, unless you change your OSes. Why is having 4 terabytes on one volume so critical? Simply config the raid as 2 volumes.
Apologies, I’m not really a Mac guy but I’m guessing that the OS is available in both 32bit and 64bit versions - and that you have the 32bit one.
There is probably an equivalent of “Help/About” or “MyComputer/Properties” you get on Windows that will tell you.
If it is 32bit can you make 2x 2TB drives - ie. use the array management to create one large Raid5 then partition it into 2 logical drives that the OS can see?
Your Mac mini must have a Core 2 Duo processor, which is a 64-bit CPU. G4, Core Solo, and Core Duo-based Mac minis are 32 bit machines.
How would configuring the RAID as two 2TB volumes work? What would happen to the fifth drive? Could it still be configured as RAID 5?
Damn, it’s a Core Duo Mac.
Ah Thanks. I assumed that RAID5 included mirroring too. That’s what I get for not looking it up myself.
Mac OS 10.5 includes both 32-bit and 64-bit support, and supports 64-bit programs and memory/drive access when running on 64-bit Intel processors (Core 2 Duo and later). The next version of Mac OS X will apparently have a 64-bit kernel as well.