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Buffalo 3TB USB strange internal sata partitioning

September 30th, 2013, 17:00

Just for info in case you have to examining such a drive in and out of the enclosure

Buffalo DriveStation External USB2.0 Hard Drive 3.0 TB

Internally this is a 3TB Seagate 512E sata drive
Barracuda 3000GB ST3000DM001
with what at first looks like strange partitioning

349GB ‘NTFS’ partition
1698GB unallocated partition
746GB unallocated partition


Externally, over USB (USB 2.0)
appears as 2.7TB drive with 4K sectors and MBR layout with a single partition

So looks like the USB interface does something non-standard
or maybe knows how to put it into native 4K mode?
There is no encryption

There is a Buffalo formatting utility that can set it up differentlt eg as a GPT disk with 512byte sectors
but by default it comes as MBR 2.7TB using 4K sectors
and a few files on it


The internal (sata) partitioning
out of the box shows

349GB ‘NTFS’ partition
1698GB unallocated partition
746GB unallocated partition

After using in drive in USB mode and filling it with 1.5TB of data
internally at the sata 512e level it still shows the same

The 349GB ‘NTFS’ partition is in fact the entire drive
but in 512e mode it is just showing the first 512byte bytes of each real sector
The rest of the data (the other 3.5k of the 4k sectors) possibly occupies the appreantly empty areas
but I haven’t looked into that more deeply yet


(This is the 3TB drive mention here
viewtopic.php?f=1&t=26068&p=183588&hilit=ST3000DM001#p183588


Another thread on here mentions something similar

viewtopic.php?f=1&t=24418&p=164592&hilit=buffalo#p164592

but there is no Inito chip or encryption on mine


They also do a 2TB version, but that just presents normal MBR partition with 512byte sectors

Re: Buffalo 3TB USB strange internal sata partitioning

September 30th, 2013, 17:09

Update

Then apparent partitioning at the sata / 512e level is it just reading the first 512bytes of the first real sector
and getting confused

As per the other post
you would need to multiply the sector numbers by 8 when you connect directly via SATA and expose the drive's 512e LBAs.

ie
4K sector 0 is 512E sectors 0-7
4K sector 1 is 512E sectors 8-15

Re: Buffalo 3TB USB strange internal sata partitioning

October 3rd, 2013, 14:05

The drive is 512E

Terminal shows
GrenadaBP LuxorPlus2 4K
Lbas: 00002BB5420C
so internally 4K

Drive passport through ata/sata interface using older tools shows
5860533168 LBAs (decimal) 2.8GB
indicating its 512E


Not sure if the Buffalo USB interface it somehow putting the drive into native 4K mode
or if its emulating 4K mode such that overall it is 4K -> 512 -> 4K

Anyone know if its possible to put these Seagate drives into native 4K mode somehow ?
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