Nil said:
I may have screwed myself. I bought a 4TB Seagate hard disk from Newegg
in a Black Friday impulse buy. My intention was to use it for backup
images, using it with my USB hard disk caddy. I've been using that
setup with 1- and 2-TB drives. I now find that XP doesn't support
drives larger than 2.something TB. In hindsight I sort of remember
that, but I never had to deal with it until now.
I'm still a little confused about what, if anything, I can do about it.
It seems that there is a driver I can download from Seagate that will
allow XP to see the drive. It also seems that I may have to partition
it into at least 2 smaller partitions. I have actually downloaded
something from Seagate called Disk Wizard, but it refused to install -
for some reason it doesn't detect the Seagate drive in the caddy.
So... is there any way to use this drive in my setup?
Seagate has DiscWizard.
http://www.seagate.com/support/downloads/beyond-2tb/
The Allocate Install, installs an Acronis driver which is *non-removable*.
It is a filter driver. You could back up your WinXP and experiment with
this, if you wish. The whole idea is, you're installing a low level driver,
which splits the 4TB drive, into a 2TB physical disk (accessible by most OSes),
plus a virtual disk (accessible for any OS with the Acronis driver).
http://imageshack.us/a/img805/4338/allocateinstall.gif
This drawing, gives an idea as to the data layout on my 3TB drive
using this Acronis software. This is actually one row of information,
but I had to fold it to fit. The first row, roughly corresponds to
the "physical disk" section. The second MBR is the beginning of the
virtual disk, that covers everything above 2TB. I was actually
able to mount the partition above 2TB in Linux, by using an
obscure offset parameter to the Linux mounter, so once Acronis
has written this setup and made an NTFS partition in the upper
section, you can actually access it from Linux (loopback mount
with offset). But Linux itself won't write a partition up there.
Linux refuses to manage things above 2.2TB in a regular operating mode.
(Maybe they support GPT, but I'm not sure about that. And at the
time, I was looking for both WinXP and other OS access.)
So once the Acronis (Seagate or WD branded) software makes
this kludge, it does provide a "foothold". The only downside of
the Linux access that way, is the abysmally slow 10MB/sec read/write
rate. The disk won't run at full speed in Linux, when operated
that way. Still, at the time, it was better than nothing. It's
like an attic in your house, where you can carry little-used goods
to the attic, never to be seen again
+------+-----+-----------------------+------------------------+--------+
| MBR | gap | 746GB NTFS partition | 1453GB NTFS partition |metadata|
+------+-----+-----------------------+------------------------+--------+
+------+------+-------+-----------------------+
| gap | MBR | gap | 746GB NTFS partition |
+------+------+-------+-----------------------+
On another occasion, I re-drew that diagram like this. I think
at the time, I'd changed the lower partition to be closer to be
2.2TB (minus enough so Win2K would recognize it or something).
This diagram just labels the gap areas a little better. I had
to search with "dd" or "hexdump" to get the details. The
1MB gap is caused by partitioning the upper partition with Acronis,
and it was using a Vista+ alignment with respect to the MBR. The
lower big partition, was set up that way by Windows, and uses the
CHS 63 sector alignment. Really confusing. The important part
to note, is the 256KB gap holds Acronis info, and that's what
some of their software uses. I had to work this out, so I
could mount the upper partition in Linux.
+------+----------------+-----------------------+
| MBR | 62 sectors gap | 2.2TB NTFS partition |
+------+----------------+-----------------------+
+------------------+------+-------------------+-------------------------+
| 262144 byte gap | MBR | ~1048576 byte gap | 746.5GB NTFS partition |
+------------------+------+-------------------+-------------------------+
And this link, opens a Adobe Flash movie, demonstrating DiscWizard.
I can't really run this right now, as a refresher, as my download
link is maxed out
http://support.seagate.com/rightnow...zard_Large_3TB_XP/DiscWizard_Large_3TB_XP.htm
These are the kinds of files, installed by Acronis. I think
part of this, is the driver that cannot be removed. A user in
an Acronis forum, showed the Acronis staff how they could fix
that, so the driver could be removed, but I don't think there
was a fix issued or anything. If the driver is removed in the
wrong order, something will BSOD. It's a bastard.
Directory of C:\Downloads\Acronis_extended_capacity_manager_virtual_3TB
08/16/2012 06:31 PM 1,561 vididr.inf
08/16/2012 06:31 PM 399 vididr_uninstall.inf
08/16/2012 06:31 PM 8,130 vididr.x86.cat
08/16/2012 06:31 PM 139,336 vididr.x86.sys
08/16/2012 06:34 PM 1,457 vidsflt.inf
08/16/2012 06:34 PM 376 vidsflt_uninstall.inf
08/16/2012 06:34 PM 1,216 vidsflt_update.inf
08/16/2012 06:34 PM 7,515 vidsflt.x86.cat
08/16/2012 06:34 PM 99,720 vidsflt.x86.sys
08/16/2012 06:43 PM 18,558 vdd_msi_32.msg
It's possible I got that driver sample, from here.
http://kb.acronis.com/content/38937
(1.8MB)
http://kb.acronis.com/system/files/content/2013/01/38937/virtualdisksetup.zip
*******
Now, in my case, that crap would not work out of the box.
My first attempt to use Seagate DiscWizard or the equivalent
Western Digital package, failed. Why ? Because I'd installed
some Acronis stuff before, an unremovable older driver was *already*
present on my WinXP! A driver incompatible with the DiscWizard
I'd just installed. I actually had to back up my current WinXP
partition, restore from a two year old (clean) image of WinXP,
then install the Seagate DiscWizard, and then the Allocate Install
step would work. <Insert your own expletive>
My status of today is - upper 1TB of my 3TB drive is
inaccessible in Windows. If I need to rummage around in
there, I have a mount command for Linux recorded somewhere (oops!).
So I can "go look up there", but it's a pretty pitiful
setup.
In Linux, this is my attempt to find the MBR of each portion.
The first MBR is at offset zero (as you'd expect). The second
(virtual) disk is at an offset of 2TB plus 256KB. And viewing
the structure, verified I'd found the correct offset.
sudo hexdump -C -n 512 /dev/sdd <--- MBR
sudo hexdump -C -s 0x20000040000 -n 512 /dev/sdd <--- MBR
Here, I bump myself along the appropriate amount for the
63 sector offset lower NTFS partition, and the 1MB offset upper
NTFS partition. Again, the NTFS header structures look the same,
so I know I've found the beginning of the NTFS stuff.
sudo hexdump -C -s 32256 -n 512 /dev/sdd <--- first partition
sudo hexdump -C -s 0x20000140000 -n 512 /dev/sdd <--- second partition
Unfortunately, I don't seem to have a record, of what my
loopback mount command looked like, to mount the partition
in Linux. The offset fed to the command would be the
0x20000140000 thing, so maybe I should search for that.
Anyway, without a lot of details, that's a review of
my experiences with this stuff. Total nightmare. A
bit like spelunking, and making it out alive...
(I used to go spelunking when I was younger, and
that's why I can have this analogy today.)
Paul
