Setting the sector size - why 4 KB?
Microsoft gives the scoop in Windows NT Boot Process and Hard Disk Constraints. Here's the skinny. The partition table which Windows uses to track hard disk partitions has a field size of 32-bits. The number of sectors in a partition is thus limited to 2^32 = 4,294,967,296. The rest is multiplication: a 4KB sector size permits a maximum partition size of 4*1,024 bytes*4,294,967,296 = 17,592,186,044,416 bytes = 16 TB. The next sector size down, 2KB, permits a 8 TB partition. Hmm, I think I could have chosen a 2KB sector size.
A few tips on setting up a 7.5 TB array - the Vtrak m500p
You read that correctly - that's 7.5 TB, as in terabyte. Yowsas... Configuration: Dell 1800, Adaptec 39320 Ultra320 SCSI card, Vtrak m500p. Here are the tips:
- When you initialize, select 4 kilobyte sectors, rather than the default 512 bytes. Windows can support huge disk sizes, but there is a limit to the number of sectors it can handle.
- Make sure to set Target ID and Lun ID in the WebPAM. I left it at the default - blank - and was unable to read the drive in Disk Manager.
- After setting the Target ID and Lun ID, you should be able to initialize the disk. Use GPT! (Otherwise, you'll only get a fraction of your storage.)
- You might timeout trying to format the drive. If so, take the SCSI speed down to 160 MBps if you are at 320. That did the trick for me - then step it back up to 320 when you start using it*.
*Yes, that makes me nervous.