Why isn't there any GPT driver for 32-bit WinXP?

I mean, there are already numerous filesystem drivers for 32-bit WinXP such
as Ext2, ReiserFS, ROMFS, HFS+, etc. But why isn't there any real GPT driver
for 32-bit WinXP? Even for non-bootable only.

Well, there's somewhat one GPT driver that's proprietary (from Paragon,
IIRC). It claims that it's compatible with 32-bit WinXP, but it turns out
that it's really not. The driver file itself requires functions from the
kernel that exist only in 64-bit WinXP or 32/64 bit Vista+.

It's fine for me if the GPT driver can't be used to boot a GPT drive. I
simply need a GPT driver to be able to access GPT drives just like MBR
drives. I don't want to use a live CD or boot into other OS including
XP64/Vista+, or use any recovery software.

JJ wrote:
I mean, there are already numerous filesystem drivers for 32-bit WinXP such
as Ext2, ReiserFS, ROMFS, HFS+, etc. But why isn't there any real GPT driver
for 32-bit WinXP? Even for non-bootable only.

Well, there's somewhat one GPT driver that's proprietary (from Paragon,
IIRC). It claims that it's compatible with 32-bit WinXP, but it turns out
that it's really not. The driver file itself requires functions from the
kernel that exist only in 64-bit WinXP or 32/64 bit Vista+.

It's fine for me if the GPT driver can't be used to boot a GPT drive. I
simply need a GPT driver to be able to access GPT drives just like MBR
drives. I don't want to use a live CD or boot into other OS including
XP64/Vista+, or use any recovery software.

I handle 3TB drives here with Acronis Capacity Manager.
It's a pretty crusty solution, and I can pretty well
guarantee you some hair loss.

What it does, is continues to use MBR technology. It
splits a 3TB dtive, into a 2.2TB physical drive, and
a 0.8TB logical drive. In Disk Management, these occupy
two different rows in the diagram.

Both Seagate and Western Digital, have a freebie written
by Acronis, that includes Capacity Manager.

Operation consists of two steps.

1) Installation of Acronis virtual driver. This is the thing
that makes the upper portion of the drive appear as a
separate hard drive.

2) "Initialization" of the drive. This consists of moving to the
2.2TB mark, writing a 256KB config block, writing an MBR for the
upper drive portion and so on.

For step (1), if you have ever used Acronis products before, then
an incompatible version of (1) may have been installed. I had to
use a backup of WinXP, go back two years (before I'd used an Acronis
product), and then installing (1) worked. It turns out, that
Acronis makes a "cleaner" program to remove that old driver.
Once you've done the research and learned of this, you use
the cleaner first, then install the Seagate/WDC package, then
use the Capacity Manager. I suffered some hair loss getting that
far. A user in the Acronis forums, taught them how to
make their "un-removable" driver, removable. And that's when
the cleaner program was born.

This method is not GPT, but it does give you *some* usage of the drive.

On Linux, you can actually "mount" the upper partition, so the
Acronis solution is (barely) cross platform. You do a loopback
mount in Linux, using an obscure offset parameter, to mount the
upper virtual partition(s). The part that sucks, is writes up
there only occur at 10MB/sec under Linux. Under Windows and using
the Acronis driver, it works better than that.

That's how I kinda sorta fixed the cross-platform problem here,
to make 3TB drives more useful. I don't have anything larger than
3TB here. Too expensive.

You will still find operation with Win2K to be "hinky". You
can't really be assured that Win2K SP4 can see the drive at
all. I tried shrinking the lower drive portion, thinking it
might be a 2.2TB limit, but I think I still had problems using
the lower portion under Win2K. And the thing is, the lower portion
of the disk is more or less bog-standard. Only the geometry information
(the declaration it is a 3TB drive), is going to cause an older
OS some grief. The contents of the lower disk portion MBR should
work better in that regard. For the other OSes you try, you may be
able to get both the upper and lower portions working. I don't
know if I've had occasion to test Win10 on this yet. I haven't been
including Win10 in any "regular" backup process. It gets backed up,
but using whatever scrap drive is sitting around. The "real" backups
go on the "big" drives.

HTH,
Paul

On Fri, 22 Jan 2016 00:35:10 -0500, Paul wrote:

I handle 3TB drives here with Acronis Capacity Manager.
It's a pretty crusty solution, and I can pretty well
guarantee you some hair loss.

What it does, is continues to use MBR technology. It
splits a 3TB dtive, into a 2.2TB physical drive, and
a 0.8TB logical drive. In Disk Management, these occupy
two different rows in the diagram.

Both Seagate and Western Digital, have a freebie written
by Acronis, that includes Capacity Manager.

Operation consists of two steps.

1) Installation of Acronis virtual driver. This is the thing
that makes the upper portion of the drive appear as a
separate hard drive.

2) "Initialization" of the drive. This consists of moving to the
2.2TB mark, writing a 256KB config block, writing an MBR for the
upper drive portion and so on.

For step (1), if you have ever used Acronis products before, then
an incompatible version of (1) may have been installed. I had to
use a backup of WinXP, go back two years (before I'd used an Acronis
product), and then installing (1) worked. It turns out, that
Acronis makes a "cleaner" program to remove that old driver.
Once you've done the research and learned of this, you use
the cleaner first, then install the Seagate/WDC package, then
use the Capacity Manager. I suffered some hair loss getting that
far. A user in the Acronis forums, taught them how to
make their "un-removable" driver, removable. And that's when
the cleaner program was born.

This method is not GPT, but it does give you *some* usage of the drive.

On Linux, you can actually "mount" the upper partition, so the
Acronis solution is (barely) cross platform. You do a loopback
mount in Linux, using an obscure offset parameter, to mount the
upper virtual partition(s). The part that sucks, is writes up
there only occur at 10MB/sec under Linux. Under Windows and using
the Acronis driver, it works better than that.

That's how I kinda sorta fixed the cross-platform problem here,
to make 3TB drives more useful. I don't have anything larger than
3TB here. Too expensive.

You will still find operation with Win2K to be "hinky". You
can't really be assured that Win2K SP4 can see the drive at
all. I tried shrinking the lower drive portion, thinking it
might be a 2.2TB limit, but I think I still had problems using
the lower portion under Win2K. And the thing is, the lower portion
of the disk is more or less bog-standard. Only the geometry information
(the declaration it is a 3TB drive), is going to cause an older
OS some grief. The contents of the lower disk portion MBR should
work better in that regard. For the other OSes you try, you may be
able to get both the upper and lower portions working. I don't
know if I've had occasion to test Win10 on this yet. I haven't been
including Win10 in any "regular" backup process. It gets backed up,
but using whatever scrap drive is sitting around. The "real" backups
go on the "big" drives.

HTH,
Paul

It looks like it's similar to OnTrack's Dynamic Drive Overlay (from
DOS+Win95 era), a driver to utilize a HDD full capacity where BIOS can't,
which uses non standard drive format where no recovery program can
recognize. That'll be worst than Microsoft's Dynamic Disk when data
corruption occured and affected the information that defines the partition
layout.

This method is not GPT, but it does give you *some* usage of the drive.

Could you give some examples about what kind of usages that aren't available
or limited?

JJ wrote:
On Fri, 22 Jan 2016 00:35:10 -0500, Paul wrote:
I handle 3TB drives here with Acronis Capacity Manager.
It's a pretty crusty solution, and I can pretty well
guarantee you some hair loss.

What it does, is continues to use MBR technology. It
splits a 3TB dtive, into a 2.2TB physical drive, and
a 0.8TB logical drive. In Disk Management, these occupy
two different rows in the diagram.

Both Seagate and Western Digital, have a freebie written
by Acronis, that includes Capacity Manager.

Operation consists of two steps.

1) Installation of Acronis virtual driver. This is the thing
that makes the upper portion of the drive appear as a
separate hard drive.

2) "Initialization" of the drive. This consists of moving to the
2.2TB mark, writing a 256KB config block, writing an MBR for the
upper drive portion and so on.

For step (1), if you have ever used Acronis products before, then
an incompatible version of (1) may have been installed. I had to
use a backup of WinXP, go back two years (before I'd used an Acronis
product), and then installing (1) worked. It turns out, that
Acronis makes a "cleaner" program to remove that old driver.
Once you've done the research and learned of this, you use
the cleaner first, then install the Seagate/WDC package, then
use the Capacity Manager. I suffered some hair loss getting that
far. A user in the Acronis forums, taught them how to
make their "un-removable" driver, removable. And that's when
the cleaner program was born.

This method is not GPT, but it does give you *some* usage of the drive.

On Linux, you can actually "mount" the upper partition, so the
Acronis solution is (barely) cross platform. You do a loopback
mount in Linux, using an obscure offset parameter, to mount the
upper virtual partition(s). The part that sucks, is writes up
there only occur at 10MB/sec under Linux. Under Windows and using
the Acronis driver, it works better than that.

That's how I kinda sorta fixed the cross-platform problem here,
to make 3TB drives more useful. I don't have anything larger than
3TB here. Too expensive.

You will still find operation with Win2K to be "hinky". You
can't really be assured that Win2K SP4 can see the drive at
all. I tried shrinking the lower drive portion, thinking it
might be a 2.2TB limit, but I think I still had problems using
the lower portion under Win2K. And the thing is, the lower portion
of the disk is more or less bog-standard. Only the geometry information
(the declaration it is a 3TB drive), is going to cause an older
OS some grief. The contents of the lower disk portion MBR should
work better in that regard. For the other OSes you try, you may be
able to get both the upper and lower portions working. I don't
know if I've had occasion to test Win10 on this yet. I haven't been
including Win10 in any "regular" backup process. It gets backed up,
but using whatever scrap drive is sitting around. The "real" backups
go on the "big" drives.

HTH,
Paul

It looks like it's similar to OnTrack's Dynamic Drive Overlay (from
DOS+Win95 era), a driver to utilize a HDD full capacity where BIOS can't,
which uses non standard drive format where no recovery program can
recognize. That'll be worst than Microsoft's Dynamic Disk when data
corruption occured and affected the information that defines the partition
layout.

This method is not GPT, but it does give you *some* usage of the drive.

Could you give some examples about what kind of usages that aren't available
or limited?

I don't think the upper section is as fast as the lower section.
(And that's taking the zoned design of the disk into account.)
It's even worse when you try the Linux mount
for cross-platform compatibility, but you can't
blame Acronis for that.

The way I end up using those disks, is the upper section is
treated like the "attic", and I put stuff up there which
I don't expect to access often. I might have to treat it
slightly differently, if the drive was even larger
than 3TB. They make some nice 6TB drives now, running
at around 220MB/sec or so. It would be interesting
to see if the Acronis technique would create three
disks out of one of those. There's nothing in theory
to prevent it.

The technique is transparent enough, that you can access
the layout with things like Linux, even though there isn't
a Linux Acronis driver for the thing. The partitions are
still partitions, and a loopback mount works. But at 10MB/sec
on the one Linux setup I tried, it would only be for emergency
recovery purposes.

Paul