Using a 3TB external drive?

I have the same issue. I have a Stardom external enclosure that supports 3tb with a Hitachi 3tb drive installed. I am running Lion and it only sees 2.2tb, not the full 3 tb. I have a feeling its a Lion issue??? Any ideas?

2.2 TB is the limit of AFP Partition scheme, try GUID Partition scheme.

I just got myself a 3tb drive and I'm having the same issue. I have four different SATA enclosures and I have the same problem in all of them (and only a Mac Mini and laptops, so no way to try internally). I'm betting all four of those are not capable of running 3TB drives. I just ordered a cheap enclosure that's listed as supporting 3TB in windows, but I'm not finding much about Mac OS X support, either for the enclosure that I ordered or in general.

I also tried reformatting the drive in each enclosure, but all would only allow 800GB.

Can anyone confirm any external enlosures that they own support 3TB?

Make sure you partition the drive, don't just erase it, you need to partition the drive as GUID partition.

It works fine here with a 3TB disk on 10.5.5.

What brand of enclosure are you using? As I said, I've tried this with four different ones, all of them partition out to 800GB. Still waiting on the one I ordered, and I'll let people know the brand and if it works or not.

Thanks, Ian

I am having the same problem. Hitachi 3TB drive, I just erased and went to partition and it says size 801.23 GB. The Partition Map Scheme is listed at GUID Partition table.

Any ideas how to access the full volume of the drive?

tony

I have encountered the same problems using 3TB drives with most external drives connected via either USB 2.0 or through Firewire 400 / 800. However, the drives that also have eSata capability DO work properly and allow use of the full external 3TB drive connected to a MacBook Pro with an external eSata PCMIA card. Thus the problem appears to be with the USB or Firewire connection in my experience, because using those connectinos the iMac or MacBook Pro can only see 800GB of a 3TB drive, but using eSata connection it can see the entire 3TB. Anyne with technical thoughts on WHY that might be?

FYI, the Macally external drive enclosure (about $67 from Amazon - see http://www.amazon.com/gp/product/B003VTZFN4) works just fine with the HItachi 3TB drives (successful with both the "green" variable speed and the continuous speed 7200 RPM Hitachi 3TB drives) connected via Firewire 800 to our 27" iMac (late 2009 model) and 17" MacBook Pro. Good luck! WES

Forgot to add that both machines are running 10.6.8, just FYI.

Great post/tip, thanks! 🙂

Some additional observations: I installed one of the HItachi 3TB (Green, variable speed) drives (yes, using GUID partition at initialization) in an older G5 Mac running 10.5, and it recognized the drive and would format it in Mac OS Extended (Journaled). However, the size was only 2.7TB, and when I tried using the G5 as an external drive in target disk mode with the 27" iMac (running 10.6), it would recognize the 150GB system HDD, but insisted on initializing the Hitachi 3TB drive as an 801.57GB drive in Mac OS Extended (Journaled).

I also tried the tarket disk mode using a 13" MacBook Pro running Lion (10.7) and it did the exact same thing.

Note, it shows the S.M.A.R.T. status as "Unknown" when erroneously depicting the drive as 801.57GB, whereas it is "verified" when connecting with eSata cables where it shows the proper 3TB size and will format properly all day long? Again, eSata works great, but no easy way to have an eSata connection in the iMacs or smaller MacBook Pros.

Note I also installed one of these Hitachi 3TB drives in a 27" iMac (late 2009) and it ran so HOT (fans going wild, WAY too noisy) that I took it out an reinstalled the original factory 2TB drive. YES, I installeld the thermal sensor correctly, and YES I used the same manufacturer for the HDD, and YES I tried the various fan speed software, but the fans were running and it was noisy just because the drive runs HOT from what I can tell, even in an external enclosure.

This is going to be a real problem as the need for larger 3TB (and more) storage exists, so I hope someone figures out why

Thanks again,

it shows the S.M.A.R.T. status as "Unknown"

USB & Firewire do not support S.M.A.R.T. status last I knew. 🙂

Just wanted to follow up that the enclosure I got works perfectly over USB (it's just a backup drive, I don't need speed). Disk Utility was happy with this enclosure and had no problems seeing, partitioning, and formatting the full 3TB. I've been cloning my previous backup drive over for the last many hours, but tested out some file copying and reading beforehand. Works well.

Cheapo Rosewill RX358 v2 ($35 from newegg) with a Hitachi Desktar 0S03208. Works fine in both 10.6.8, and 10.7.1. Haven't tried anything but USB.

Thanks for the other helpful posts.

I have a MacBook Pro (Mid 2010, Snow Leopard 10.6.8) and I bought a Freecom external HD Quattro 3.0, 3TB model, which have USB2.0/3.0, FW400/800 and eSATA connections. The enclosed HD is an Hitachi Deskstar 5K3000.

If I connect the HD through USB2.0 the OS recognizes it as a 3TB HD. I can format it, create partitions, etc... with no problem.

But if I connect the HD through the FW800 the OS recognizes it as a 2.2TB HD! No matter of GUID partition table and the like.

I tried also to create 2 partition 1.5TB each using USB2.0 and then connect through FW800 but all I can see is just the first partition. And still the OS (and DiskUtil) recognizes it as a 2,2TB HD.

I booted Linux Ubuntu 11.10 64-bit (through the Live CD) and I connected the HD through FW800. Linux recognizes the HD as a 3TB HD! I can format it, create partitions, etc.. using GParted with no problem.

Partitions created with Linux are recognized (the whole 3TB) by Mac OS if I use USB2.0, but using FW800 the HD is always recognized as a 2.2TB capacity disk.

I think this means that there are no hardware limitation, neither in the MacBook Pro nor in the external HD.

It seems it's a problem in the FW800 software/drivers in Mac OS.

Hope this help.