Do you know the actual size of the HPA in sectors? One way to get this is to examine the Devices page and look at the device identifier of the disk(s) with HPA. The identifer is in parenthesis, for example in the line below, the identifer is "sdh":
disk1 device: pci-0000:00:1f.5-scsi-0:0:0:0 host4 (sdh) ST380811AS_5PS2P6J7
Now from the console or telnet session, type this command:
hdparm -N /dev/<identifier>
For the disk above I would type:
hdparm -N /dev/sdh
Please post output of this command.
HPA has been expunged, this is current output of 3 disks that had it (hda, sdm, sdl)
Tower login: root
Linux 2.6.32.9-unRAID.
root@Tower:~# hdparm -N /dev/hda
/dev/hda:
The running kernel lacks CONFIG_IDE_TASK_IOCTL support for this device.
READ_NATIVE_MAX_ADDRESS_EXT failed: Invalid argument
root@Tower:~# hdparm -N /dev/sdm
/dev/sdm:
max sectors = 976773168/3694640(976773168?), HPA setting seems invalid (buggy kernel device driver?)
root@Tower:~# hdparm -N /dev/sdl
/dev/sdl:
max sectors = 976773168/3694640(976773168?), HPA setting seems invalid (buggy kernel device driver?)
root@Tower:~#
Output of 2 other 500GB that never had HPA. (sdk, sdn)
root@Tower:~# hdparm -N /dev/sdk
/dev/sdk:
max sectors = 976773168/3694640(976773168?), HPA setting seems invalid (buggy kernel device driver?)
root@Tower:~# hdparm -N /dev/sdn
/dev/sdn:
max sectors = 976773168/3694640(976773168?), HPA setting seems invalid (buggy kernel device driver?)
root@Tower:~#
Now I remember, the difference of 4 KB showed up immediately upon 1st boot of 4.7beta1, before '4K alignment' was selected.