3TB and Linux?

[Lennart Sorensen]

On Wed, Jan 05, 2011 at 08:18:34AM -0800, William Park wrote:
> Anyone using 3TB harddisk on Linux?
> Do you have to use any special PCIe card or vendor supplied drivers?
> Is the disk on SATA port or USB port?
> 
> Specs for WD 3TB disk says that Linux needs special PCIe card (hinting that it's 
> chipset issue) which ships with the WD 3TB disk.  But, specs for Hitachi 3TB 
> disk doesn't mention about requiring special PCIe card, but does mention whole 
> other things about GUID partition table, UEFI BIOS, etc.

GUID partition table is required.

UEIF BIOS is required to boot from the drive if running windows (which
must be 64bit in that case).  Windows can use it as a data drive just
fine.

Linux with grub2 can boot from it without UEFI just fine.  I currently
have a few servers booting from a hardware raid that is 2.2TB using GUID
partition tables, and it's fine.  Plain old BIOS.

I don't know of any controller issues to do with disks over 2TB.
Some USB controllers in external enclosures might have issues, no idea.

I see mentions of LBA32 which seems silly since LBA in the past has
always been LBA28 for old IDE and LBA48 for modern IDE and SCSI, and I
can't believe SATA would use anything other than LBA48.  Some people are
talking about LBA64, which seems like nonsense.  They also claim LBA48
can only do 2.8TB, which is wrong.  2^48 bytes would be 2.8TB, but LBA
is sector addreses, so 2^48 sectors using 512byte sectors is 1430TB.
It seems the real problem is some drivers only support 2^48 byte access
for some reason.  Apparently some designs only support a 32bit sector
number internally, which means 2^32 sectors of 512 bytes which is 2TB.
Not an LBA problem at all though, since the interface is LBA48, just an
internal design problem.

-- 
Len Sorensen
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