Hard disk case: Capacity is not correct

This example shows the status the status of a 3 TB hard disk, used with an older USB enclosure/adapter/docking station.

Hard disk problems reported

Compatibility problem overview

Older hardware and/or operating systems/drivers may not be fully compatible with high capacity hard disks. Hard Disk Sentinel is the ONLY solution to be notified about such possible compatibility problems, without Hard Disk Sentinel the problem may remain completely undetectable until data loss.

Of course the problem is not related/caused by Hard Disk Sentinel and Hard Disk Sentinel can't fix the compatibility problem caused by some hardware/software elements, but can show this warning to indicate that there is a serious problem which require immediate attention.

Hard disk "capacity is not correct" problem may happen with any hard disk from any manufacturer over 2 TB and both under older Windows (XP / 2003) and newer Windows (7 / 8 / 10) systems as well.

Compatibility problem description

Older USB 2.0 and even some USB 3.0 adapters/enclosures/docking stations may not be fully compatible with hard disks over 2 TB in capacity.
When such combination of older USB adapters and high capacity hard disk drives used, the USB adapter may report smaller capacity than expected to the operating system as it does not use enough bits when detection and reporting the hard disk drive geometry and accessing data sectors.

Technically: older hard disk controllers/adapters/enclosures address the hard disk capacity and sectors in 32 bits only. It means they are able to address sectors up to 232-1, which is 4294967295 sectors. By 512 bytes/sector, it is 2199023255040 bytes, slightly more than 2 TB (2199023255040 / 1024 / 1024 / 1024).

So compatibility problem occurs when hard disks over that capacity (generally 3 TB and above) used.

More seriously, accessing sectors over the reported capacity does not generate any errors, this seems possible and working - but actually due to a sector address overflow, the beginning of the hard disk is accessed (read/written) again - instead of the end of the data area.

The result is that when the user starts to fill the logical drive (partition) with data and reaches the point where the overflow occurs, then the first sectors of the hard disk will be overwritten, causing serious and unrecoverable data loss - as the original data sectors (including Master Boot Record/partition table, MFT, directory entries, files, etc.) are all overwritten.

The problem may remain undetected until a complete power cycle (of the enclosure and/or the whole computer) when the cache flushed. Then, after restart, the hard disk seems not initialised and the partition, files are lost - and even data recovery tools/companies can't help as the original data area is overwritten - clearing all previously stored information.

Hard Disk Sentinel detects possible compatibility problems between these older devices (like controllers/enclosures/adapters/docking stations) and hard disks and immediately report the problem to increase attention.

As this problem is not really related to the hard disk, the hard disk drive Health and Performance % values are unaffected - but the immediate alert and the text description should suggest to stop using the current configuration immediately and improve the situation by changing the configuration (for example replacing the USB adapter/enclosure).

Other possible situations when "Capacity is not correct" message displayed

In some cases, hard disk controllers and their drivers may also not handle high capacity hard disks properly: due to addressing limit of the hard disk sectors, they may also have similar problem. If this happens, it is recommended to update the driver of the current hard disk controller (displayed on the Information page in Hard Disk Sentinel with its current driver date and version) from the Driver Zone page, which designed exactly to offer the best useful drivers for various hard disk controllers/chipsets/motherboards (which may not be the latest one in many cases).

Also under older Windows systems (like Windows XP) the previously mentioned compatibility issue may occur (even if the USB adapter is perfect and compatible with the high capacity hard disk in other, newer systems) and then Hard Disk Sentinel also shows the warning - and this is the reason of the It is recommended to check and modify the configuration or upgrade the operating system, hard disk controller and/or drivers to safely use this device section.

Verification of the problem

By default, there are no other indication of problem found, except that Hard Disk Sentinel displays the warning. But it is possible to verify the situation this way:

After right click on Computer, select Manage -> Disk Management option and then select the appropriate hard disk, it is possible to verify that Windows detected the total capacity of the hard disk as 746 GB:

Hard Disk Drive capacity is 746 GB.

Even worse, that it may show that (if the hard disk partitioned and formatted in an other system) the 746 GB hard disk contains the partition of the total capacity of the hard disk (2794 GB in this situation) - which does not seem correct.

Note that 1 GB = 1024 x 1024 x 1024 bytes.

And other way to "verify" the problem is by filling the logical drive (partition) completely: after high amount of data (2048 GB data is surely enough, in some cases even less are enough) copied to the hard disk, the partition and all previously saved files/folders will be lost. DO NOT attempt this if you have important data on the appropriate hard disk!




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