[PLUG] Hard drive: size discrepancy

[Rich Shepard]

I have a Seagate Barracuda XT with marked capacity of 3000GB. It was in a
sealed external enclosure which I disassembled.

The drive had a MBR/DOS partition table type. I used gparted to change
that to GPT. However, gparted sees only 746.52GB on the drive. It still has
a DOS/MBR boot sector.

What can I do to find the missing space on the drive and remove the MBR
since it's no longer needed.

TIA,

Rich

[Galen Seitz]

  I have a Seagate Barracuda XT with marked capacity of 3000GB. It was
in a
sealed external enclosure which I disassembled.
  The drive had a MBR/DOS partition table type. I used gparted to change
that to GPT. However, gparted sees only 746.52GB on the drive. It still has
a DOS/MBR boot sector.
  What can I do to find the missing space on the drive and remove the MBR
since it's no longer needed.

dd if=/dev/zero of=/dev/my_raw_scratch_disk bs=1M count=1

This will zero the first megabyte of the disk, wiping any existing
partition table. Then try partitioning again. Be sure you are using
the whole device and not a partion (i.e. /dev/sdX and not /dev/sdXN).


galen

[Rich Shepard]

Post by Galen Seitz
dd if=/dev/zero of=/dev/my_raw_scratch_disk bs=1M count=1
This will zero the first megabyte of the disk, wiping any existing
partition table. Then try partitioning again. Be sure you are using the
whole device and not a partion (i.e. /dev/sdX and not /dev/sdXN).

galen,

Thank you. The drive is seen as /dev/sdb and that's why I was puzzled that
not all 3T were seen.

A task for tomorrow morning.

Best regards,

Rich

[Rich Shepard]

Post by Galen Seitz
dd if=/dev/zero of=/dev/my_raw_scratch_disk bs=1M count=1

Galen,

Unfortunately, this makes no difference. gparted still sees only 750G. The
device information it shows is:

Model: ST330006 51AS
Serial: None
Size: 746.52GiB
Path: /dev/sdb

Partition table: gpt
Heads: 255
Sectors/track: 63
Cylinders: 97451
Total sectors: 1565565872
Sector size: 512

I no longer remember how to translate these numbers to disk capacity, but
it's missing about 2.25T.

Regards,

Rich

[Rich Shepard]

Post by Rich Shepard
I no longer remember how to translate these numbers to disk capacity, but
it's missing about 2.25T.

Ah, wait. I just had a thought that might be inportant. The drive is
connected to the old desktop and with an MBR partition type it may not be
able to see the 3T, although it did when the drive was in its original case.
(Might have been firmware foo in the enclosure.)

Will try on the new desktop.

Rich

[Rich Shepard]

Post by Rich Shepard
Will try on the new desktop.

Sigh. No difference.

Anything else I can try before this goes to Free Geek?

Rich

[Galen Seitz]

 Will try on the new desktop.

  Sigh. No difference.
  Anything else I can try before this goes to Free Geek?

Do you have the parted command available? I doubt it will make a
difference, but it's worth a try. That's what I use here.


galen

[Rich Shepard]

Do you have the parted command available? I doubt it will make a
difference, but it's worth a try. That's what I use here.

galen.

I used gparted and parted is also available. I've used cfdisk on new
drives to create a partition table type and partitions, then mke2fs to
install a file system on them. Haven't used parted/gparted before now.

Thanks,

Rich

[Bill Barry]

Post by Rich Shepard

Do you have the parted command available? I doubt it will make a
difference, but it's worth a try. That's what I use here.

galen.
I used gparted and parted is also available. I've used cfdisk on new
drives to create a partition table type and partitions, then mke2fs to
install a file system on them. Haven't used parted/gparted before now.
Thanks,
Rich

These might reveal something.

fdisk -l /dev/sdb

lsblk

Bill

[Rich Shepard]

Post by Bill Barry
These might reveal something.
fdisk -l /dev/sdb
lsblk

Bill,

Thank you. I looked at the output of both before writing to the mail list.
Each shows ~750G available.

Regards,

Rich

[Galen Seitz]

Post by Bill Barry
These might reveal something.
fdisk -l /dev/sdb
lsblk

Bill,
  Thank you. I looked at the output of both before writing to the mail
list.
Each shows ~750G available.

sudo parted /dev/my_disk print

What does this show for the size of the disk?


galen

[Galen Seitz]

Post by Galen Seitz

Post by Bill Barry
These might reveal something.
fdisk -l /dev/sdb
lsblk

Bill,
   Thank you. I looked at the output of both before writing to the
mail list.
Each shows ~750G available.

sudo parted /dev/my_disk print
What does this show for the size of the disk?
galen

How is the disk connected to your system? USB? Perhaps this applies:

<https://ubuntuforums.org/showthread.php?t=1840014>


galen

[Rich Shepard]

Post by Galen Seitz
<https://ubuntuforums.org/showthread.php?t=1840014>

galen,

Looks like drives sold in external USB enclosures do have different
firmware on the drives. As a response on that thread wrote, "There have been
several posts about this type of problem in the past on this forum. The
usual culprit is a USB drive enclosure that has a 32-bit limitation. ...
I've never heard of this problem showing up in Linux with internal drives,
but it's theoretically possible."

So I guess it's now a 750G drive since it started life as an external
drive and I intended it to remain so, but in a multi-drive bay.

Thanks very much,

Rich

[Tomas Kuchta]

Disks we're not limited to <3 TB on 32b systems. The only limit there ever
was old MS FAT.

T

Post by Rich Shepard

Post by Galen Seitz
<https://ubuntuforums.org/showthread.php?t=1840014>

galen,
Looks like drives sold in external USB enclosures do have different
firmware on the drives. As a response on that thread wrote, "There have been
several posts about this type of problem in the past on this forum. The
usual culprit is a USB drive enclosure that has a 32-bit limitation. ...
I've never heard of this problem showing up in Linux with internal drives,
but it's theoretically possible."
So I guess it's now a 750G drive since it started life as an external
drive and I intended it to remain so, but in a multi-drive bay.
Thanks very much,
Rich
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http://lists.pdxlinux.org/mailman/listinfo/plug

[Rich Shepard]

Post by Tomas Kuchta
Disks we're not limited to <3 TB on 32b systems. The only limit there ever
was old MS FAT.

Tomas,

Whatever the reason, this one does not want to reveal all its capabilites.
Yet. I checked the Seagate site (as the disk label suggests) and found only
information for Windows users on installation, formatting, and similar
topics. No e-mail contact for non-warranty repair technical support. So,
time to ask on a hardware-related forum (perhaps Tom's Hardware or LQ).

MS FAT is an appropriate description.

Regards,

Rich

[Galen Seitz]

Post by Tomas Kuchta
Disks we're not limited to <3 TB on 32b systems. The only limit there ever
was old MS FAT.

The 32 bit limit that was mentioned in an Ubuntu forum relates to some
USB<->SATA converters. Apparently some controllers have internal sector
registers that are only 32 bits.

Number of 512 byte sectors in 3 TB drive
3e12 / 512 = 5.9e9 sectors

Assuming 32 bit wrapping (modulo 2^32)
5.9e9 - 2^32 = 1.6e9 sectors

Drive size after wrapping
1.6e9 * 512 = 801 GB


galen

[Rich Shepard]

Post by Galen Seitz
The 32 bit limit that was mentioned in an Ubuntu forum relates to some
USB<->SATA converters. Apparently some controllers have internal sector
registers that are only 32 bits.
Number of 512 byte sectors in 3 TB drive
3e12 / 512 = 5.9e9 sectors
Assuming 32 bit wrapping (modulo 2^32)
5.9e9 - 2^32 = 1.6e9 sectors
Drive size after wrapping
1.6e9 * 512 = 801 GB

Galen,

So the sector size should be increased?

Thanks,

Rich

[Galen Seitz]

Post by Rich Shepard

Post by Galen Seitz
The 32 bit limit that was mentioned in an Ubuntu forum relates to some
USB<->SATA converters. Apparently some controllers have internal sector
registers that are only 32 bits.
Number of 512 byte sectors in 3 TB drive
3e12 / 512 = 5.9e9 sectors
Assuming 32 bit wrapping (modulo 2^32)
5.9e9 - 2^32 = 1.6e9 sectors
Drive size after wrapping
1.6e9 * 512 = 801 GB

Galen,
  So the sector size should be increased?

No, you can't change the sector size. If you have the disk directly
connected to your system using SATA, I can't explain why you are having
this problem.

If you can, connect the disk via SATA and post the output of this command:
sudo parted /dev/my_disk print


galen

[Rich Shepard]

Post by Galen Seitz
sudo parted /dev/my_disk print

Galen,

Aha! it's not internally connected. The multibay enclosure has both USB
and SATA connectors; I've been using the USB one. I'll find an external SATA
port (I think the motherboard has one) and use that.

Best regards,

Rich

[Rich Shepard]

No, you can't change the sector size. If you have the disk directly
connected to your system using SATA, I can't explain why you are having
this problem.

Galen,

It's a naked, internal drive but the adapter I've been using to connect
drives to hosts is 10-12 years old usb2. Just ordered a usb3 to sata
replacement. As this is the only drive > 2T that I've partitioned and
formatted with the current adapter it's highly likely that it has the 2T
limit.

When the new adapter arrives I'll post results.

Regards,

Rich

[Tomas Kuchta]

How old is your disk with it's SATA controller? If it is newer than 15
years - yes, 2003 - then your computer with relatively recent Linux should
see it as 3TB disk without any issues.

The math you are working with has never been applicable this way. There
used to be LBA (or whatever it was called) partition size limit. That Linux
could work around those days by LVM.

Didn't you say, in your earlier post, that you are connecting the disk to
your new system from 2018? In that case all should work as intended.

Try to ask some of your Linux or windows buddies to plug it to their system
and see if you get different result. Alternatively, get yourself different
SATA cable and try it on Knoppix.

I see the frustration, but we are pretty off the chart in trying to find
made up reasons for your kind of behavior.

Perhaps also put the disk back to it's original enclosure and check if it
works as intended 3TB disk on Windows box before returning it.

Hope it is helpful,
Tomas

Post by Galen Seitz

Post by Tomas Kuchta
Disks we're not limited to <3 TB on 32b systems. The only limit there

ever

Post by Tomas Kuchta
was old MS FAT.

The 32 bit limit that was mentioned in an Ubuntu forum relates to some
USB<->SATA converters. Apparently some controllers have internal sector
registers that are only 32 bits.
Number of 512 byte sectors in 3 TB drive
3e12 / 512 = 5.9e9 sectors
Assuming 32 bit wrapping (modulo 2^32)
5.9e9 - 2^32 = 1.6e9 sectors
Drive size after wrapping
1.6e9 * 512 = 801 GB
galen
--
Galen Seitz
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PLUG mailing list
http://lists.pdxlinux.org/mailman/listinfo/plug

[Rich Shepard]

Post by Galen Seitz
sudo parted /dev/my_disk print
What does this show for the size of the disk?

galen,

I used parted -l /dev/sdc. The tool showed all three disks; it reported sdc
having 802G capacity. parted /dev/sdc print reports the same 802G.

Seems like this drive just will not allow access to the full 3T when
outside of its original case. Perhaps Seagate builds the firmware
differently when the drive is sold in an external enclosure rather than for
internal use in a desktop.

So, since we seem to have exhausted possibilities (fdisk, cfdisk, lsblk,
parted, gparted) I need to replace it with a known-good internal hard drive.
Will order from Newegg later today.

Thanks,

Rich