We hade been using a WDC WD40 PURZ-85TTDY0 in a cheap NVR, which did not work as expected, so we decided to use the disk in an external enclosure with USB as an external drive for Backups.
In the NVR, the disk showed a free capacity of about 3,6 TB. While this is not the expected 4TB, there may have been part of it used with the device’s OS.
After installing it in the enclosure, it showed a capacity of only about 1.6TB. I found that the drive has to be formatted as GPT to show more than 2TB, which I did.
Although it has now been formated as GPT, it still shows only a capacity of ~1.6TB. We have tried various methods, clearing the disk & reformatting with different partitioning tools including diskpart and 3rd party tools, but there seems to be no way to use its full capacity. Maybe there is a specific tool that we can install? I have also looked for a possible driver update, but have not found anything on WD’s website.
BTW, the external enclosure is not the latest model. I worked fine with a 500 GB disk. Could it be that older enclosures limit the useable capacity?
Edited Answer Below
Joey, I think you misunderstood the issue. I have no intent to use any NVR, neither the old one nor a new one, because I bought another system. That’s why I took out the 4TB HD and put it in a USB enclosure which I want to use as an external backup drive.
The NVR actually showed 3.6TB free capacity on this disk, so it did recognize it correctly. The problem is that now, using the same disk as an external drive, it has only 1.6TB available, even after making sure it is GPT.
I thought I had described this well.
Oops, apologies
Same deal with 3rd Party USB External Enclosures … some (older ones) only support 2TB, others support 4TB or greater.
I remember before buying an external enclousure for a 4TB Hard drive i had, and carefully checked the product description/specifications to find out what capacity it supported. Once i found a cheap one that supported 4TB, i bought it.
That’s what I suspected, thanks. Which type did you use?
I bought an Orico (it was cheap) … not the exact model below (it was years ago)
Scroll down the page half way and it states “Support up to 10TB”
https://www.orico.cc/usmobile/product/detail/id/3518
Only negative about the Orico Enclosure is it’s made of plastic and can get quite warm … so i leave the top cover off for extended usage
Thanks, I will check this out. Maybe will find a metal enclosure, just need to look at the TB spec.
I hope this will work.
If whatever brand you decide to buy advertises 4TB or higher capacity
It should definitely work 
