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I can use a 5 TB HDD in XP - how is that possible?


Snear

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1 hour ago, bphlpt said:

@Snear, you say that those disks "work" on the one "magical" XP system, but don't on the other XP systems or on Win7. When you try them on those other systems, do you move the sharkoon drive bay to those other systems, or do you connect the drives to those other systems in some other manner?

Cheers and Regards

I did not move the sharkoon drive bay, but connected them directory to a SATA port. But as already mentioned - it works on the "magical" XP system without a drive bay. BTW, I got three USB-HDD-enclosures for SATA drives and tried them out, but the drives never show up in the disk management tool.

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13 minutes ago, dencorso said:

No need for that... instead, I do want to know exactly which motherboard (= Model, Manufacturer) are you using, please. :)

Asus M5A88-M running in AHCI mode.

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10 hours ago, Snear said:

Asus M5A88-M running in AHCI mode.

MBRview shows one partition with Num LBA: 2441879937
http://reboot.pro/topic/8734-tiny-hexer-scripts/

2441879937*2048/1024^2 ~ 4769297

Stange, yes there are 2048 bytes per sector. 

If it's not the hot swap case, then there has to be another reason.
This can be a driver, e.g. the previous referenced  DiscWizard Extended Capacity Manager.

If no one ist installed, then there are the ahci driver still. 
Does ahcix86.sys creates virtual  2048 bytes per sector,  given a hard disk greater 4 TiB?


Try, write the full disk.
Be aware,  if you swap this hard disk to another system, reading files may fail.
Backup the data.

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2 hours ago, cdob said:

If it's not the hot swap case, then there has to be another reason.

This can be a driver, e.g. the previous referenced  DiscWizard Extended Capacity Manager.

If no one ist installed, then there are the ahci driver still. 
Does ahcix86.sys creates virtual  2048 bytes per sector,  given a hard disk greater 4 TiB?


Try, write the full disk.
Be aware,  if you swap this hard disk to another system, reading files may fail.
Backup the data.

It's not the hot swap case - it works without. I have never heard of the DiscWizard Extended Capacity Manager - we can rule that one out, too.

I am currently filling the entire disc with data to check out if it's actually usable. And I am going to use the same ahcix86.sys on my other PCs with Win XP Pro and switching them to AHCI (they are running in IDE mode right now). I will also try to read the drive with linux. It might take 2 or 3 days until my next post, but I will continue to report about any progress I made.

And of course, I am not going to use the 5 TB HDD for important data until I exactly know what's going on...

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Good. :)

The mbr is fine.

In the MBR the partition entry is (lba) 63-2441879937, and the 2441879937=0x918C2181 is compatible with the "number sectors" of 0x918C2180 that is in the output of   

"fsutil fsinfo ntfsinfo" (the excess sector is the $BootMirr which is inside the partition but outside the volume).

Now, 5 TB are roughly 5,000,000,000,000 which divided by (2441879937+63)=2,441,880,000 makes 2047,60 which is evidently 2048 bytes/sector (and there may be a few excess sectors after the partition, so it is not possible to calculate exactly the capacity from these data) .

About the "fsutil fsinfo ntfsinfo" it has been modified in later OS version (I seem to remember from 7) to display some slightly different info, if you can you could try a later version that has the distinction between physical sectors and logical sectors, *like*:

https://docs.microsoft.com/en-us/windows/win32/w8cookbook/advanced-format--4k--disk-compatibility-update

You could run ntfsinfo by sysinternals (don't worry the 32 bit version runs on XP just fine):

https://docs.microsoft.com/en-us/sysinternals/downloads/ntfsinfo

so at least we'll have the data directly in decimal.

So that disk seemingly exposes 2048 bytes per sector (but it cannot be the disk if the same disk on another PC doesn't), so it must be something in the drivers on that specific OS instance/install , but I wonder what could cause that. :unsure:

I mean, if you installed some "special" tool and you cannot remember, it must still be there and it should be possible to find it (but it would be queer that it is the "intended effect" of a "special tool", as by now, half the internet would be talking about it) so it is maybe a "side effect" of "something" (yes, not a very accurate definition I know) :dubbio:.

jaclaz

 

 

 

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Some news:

  • No tools involved, it works with a clean Win XP Pro Installation including all POSReady updates.
  • It requires AHCI to be enabled . If I switch to Legacy IDE in the BIOS and install the same version of Windows, it won't work. Of course, I need to integrate ahcix86.sys in order to boot from a SATA drive. Please note that I did not yet try to boot from the 3TB or 5TB drive. I only use them as data disks.
  • It works on Asus M5A88-M (SB850) and J&W Minix 780G (SB700) mainboard.
  • The drive is not readable using linux. I tried dozens of tools. No success.
  • I can use the entire disk space.

I don't have any Intel hardware to test. I am going to test another mainboard AM3+ mainboard with a SB950, an Asus AM1 board and a HP Thin Client T610.

Happy new year!

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Yes and no (about bootability/readability).

Bootable it won't be (in BIOS), the issue here is - besides the sector data "sensed" (and *somehow* translated to 2048 bytes) that the actual MBR code is "hardcoded" to 512 bytes/sector and will simply fail. (which does not mean that it is possible - in theory - to write a specific/special   MBR code, but IF - as it seems - the magic translation is in one of the Windows drivers, it has to be seen - at BIOS level - which sector size is actually seen).

Later (when you will have made all the experiments in "non bootable" mode) we can see what happens at BIOS level using grub4dos.

Readability in Linux might instead be possible, the MBR - as said and as seen in various experiments with 4096 bytes sectored disks - is "sector size agnostic" (or - if you prefer -  there is no field anywhere to specify the sector size at MBR level and 512 bytes is assumed by everyone) BUT the filesystem (be it NTFS or not) has a field for sector size, so at that level it is well possible to have a non-512 bytes/sector perfectly readable, in the end it depends whether the Linux NTFS (or other filesystem) driver:

1) is written "properly" and takes the sector size field into account
2) can (the actual OS) mount the volume as "superfloppy" (i.e. bypassing the MBR, mounting the partition/volume only)

In a similar (but actually completely different) situation I devised a (half-@§§ed but working) special formatting scheme allowing to "switch" a same disk between 512 and 4096 bytes sector, the case was an external case with both a USB and an e-sata connection where one of the interface exposed one sector size and the other the other, here:

The same approach (if only condition #1 above is fulfilled) could be adapted to this case (and it should/could  work both under Linux and on other NT based OS, though unfortunately most probably not under XP if the volume is over the same classic 2.2 TB "limit").

jaclaz 

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21 hours ago, Snear said:

If I switch to Legacy IDE in the BIOS and install the same version of Windows, it won't work.

What happens at IDE mode? Does device manger list a hard disk? Does disk manager list the hard disk?

The Asus M5A88-M manual describes a SATA Block (Multi-Sector Trasfer) mode.

Long shot, guessed: This leads to a assumption:
may this creates the 2048 sectors at a 5 TiB disk at BIOS level?
The Windows IDE driver fails at this? The AMD AHCI dirver support this?


The default is [Auto]. Multi sectors are transferred. Do you use Auto mode?
What happens at [Disabled] mode?

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On 1/2/2020 at 5:46 PM, cdob said:

What happens at IDE mode? Does device manger list a hard disk? Does disk manager list the hard disk?

The disk manager does list the hard disc in IDE mode, but it is shown with the wrong size.

I made some further tests with the J&W Minix 780G (SB700) mainboard.

In all tests in AHCI, I used the driver rcxpahci.sys V6.1.3.00035 from 2014. I integrated this driver in order to let the drive show up during the installation of XP Pro. What I did not recognze so far: it is actually only being used as a textmode driver. XP Pro SP3 has its own PNP AHCI driver: ahcix86.sys V3.1.1540.86.

I then tried a different one: ahcix86.sys V3.2.1540.35 from 2009. And suprise - I do not see the 5TB drive in the disk manager. It is only shown in the device manager.

It seems like the AHCI driver is responsible for creating some kind of virtual sectors, but it looks like it's version dependent. I have two more versions to check: 3.1.1540.25 and 3.1.1540.127
 

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The V3.1.1540.25 AHCI driver works - the 5TB HDD is accessible. V3.1.1540.127 is corrupted in some way. I can't make it run.

If I switch back to V3.2.1540.35, the drive vanishes from the disk manager.

 

 

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