Nuclex

I'm running a small home server that, amongst many other things, stores my music collection, software, virtual machines and more. As any computer user is able to testify, no matter how much hard drive space you've got on a rig, you will run out of it eventually.

So last week, I decided to replace my aging 500 GB drives with three brand new 2 TB drives (my choice fell on Western Digital's WD2000EARS drives, btw - only 5400 RPM but dirt cheap and because this is for long-term storage, all I want is space, not speed). I partitioned all three of them using the exact same commands in fdisk (launched with fdisk -c -u /dev/sd*). Before I did that, all drives appeared with identical informations when I ran fdisk -c -u -l. Now?

The first drive now has 18 heads and 6 sectors/track:

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
18 heads, 6 sectors/track, 36176196 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa28d6fec

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048  3906996224  1953497088+  83  Linux

The second one got 69 heads and also 6 sectors/track:

Disk /dev/sdd: 2000.4 GB, 2000398934016 bytes
69 heads, 6 sectors/track, 9437268 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x78f7deaf

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1            2048  3906996224  1953497088+  83  Linux

And the third one got 18 heads again, but only 3 sectors/track:

Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes
18 heads, 3 sectors/track, 72352392 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xbef707e2

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1            2048  3906996224  1953497088+  83  Linux

I know that heads and sectors on modern hard drives no longer have any relationship to the physical number of heads and sectors on the drive, but why do I get 3 different results from running the same command 3 times, on 3 identical drives?

They all have the same capacity in the end and my raid array is running fine, but this confuses the hell out of me :D