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Bill
Premium,VIP
join:2001-12-09
reply to sdghty

Re: Maximum Hard Drive Size for Windows XP 32 bit

To be more specific (because I'm sure everybody cares ), the limitation is in the "total sectors" field in the MBR. It's only 8 bytes (32 bits), which provides for a maximum value of 4,294,967,296 sectors. And at 512 bytes per sector, that comes out to 2TB. 4K sector size ATA disks do exist, but I have only seen them used in CE devices.

Another problem we'll run into in the future is when drives get larger than 2TB, you won't be able to create any new partitions after the 2TB mark on the drive! The "relative sectors" (offset) is also a 8 byte value, so you can't give it a relative address larger than 2TB. But we should all be using GPT instead of MBR by then



sdgthy

@optonline.net

said by Bill:

To be more specific (because I'm sure everybody cares ), the limitation is in the "total sectors" field in the MBR. It's only 8 bytes (32 bits), which provides for a maximum value of 4,294,967,296 sectors. And at 512 bytes per sector, that comes out to 2TB. 4K sector size ATA disks do exist, but I have only seen them used in CE devices.
And some raid cards, I just setup 8 1TB drives for a 6.36TB raid5 array, as reported by windows, on a w2k system. I didn't get that deep into it as the OPs question was whether 2TB was a drive limit or total of all drives limit. Without a doubt, it's the former.

said by Bill:

Another problem we'll run into in the future is when drives get larger than 2TB, you won't be able to create any new partitions after the 2TB mark on the drive! The "relative sectors" (offset) is also a 8 byte value, so you can't give it a relative address larger than 2TB. But we should all be using GPT instead of MBR by then
I suspect that'll be quite some time from now. It takes a huge amount of data to fill even 2TB, and I'm sure the average user won't run into that problem for a good number of years yet. And I suspect that point won't be quite as bad as all the LBA issues have been.


Voltron

join:2007-08-04
Bloomington, IN

Hello, sdgthy:

I am installing an Arena Maxtronic hardware-based RAID system (SA-3340S), with 8 one TB SATA drives, connected via an Adaptec 29320LPE (U-320 SCSI) host bus adapter, on a Windows XP Professional (with SP2) system. I want to do what you did with your W2K system, which is to create one array that encompasses the entire capacity of the eight drives, in a RAID 5 configuration. What settings did you have to change on your SCSI adapter card and/or within your RAID enclosure, to allow W2K to see the entire 8 TB (6.36 TB) capacity, without creating multiple LUNS, slices, etc.?

Thank you so much for your assistance, in advance.

--Dylan



sdgthy

@optonline.net

1 recommendation

I used an Areca ARC-1160 which has a setting to present the array as having 4K sectors. That and the performance where the primary reasons I went with an Areca card.

Of the raid cards I considered, the Areca was the only one that had that option. Honestly, I haven't looked at an Adaptec RAID card in awhile as I haven't been too impressed in the past. I never got a ZCR card to work properly in this system. And the issues I had with a 2940 & 3950 in another system should have taught me that. Although I am starting to hear good things about some of the newer cards.