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Windows can find drive size

Posted: 18 Oct 2018, 16:56
by Markmilleru2
Hello – Any insight with this would be appreciate.

About a year ago I replaced the 2 hard drives for my win7 os. Both were 1tb – first drive is the boot drive and the second was just for data – the boot drive was having some sort of I/O issues so, I replaced both drive. I replaced the boot drive with a 1tb drive – and since the second
drive was just a “data” drive – I replaced the 1tb drive with a 3tb drive

after the new hardware installed, I started up the computer — I was able to clone the boot drive and win7 started up fine.

So now I wanted to format the second drive, but windows was telling me the the size of the
second disk was just 768gb – I then reboot, when to the BIOS and that reported the drive as 3TB.

I then took out the 3tb drive and formatted on another win7 machine – creating a GPT and it formatted the full 3tb –

I then put that drive back in the computer and window now sees a 3tb drive, tools like testdisk
still see the size as 768gb

It seems to be working OK I was able to write files to it and last time I checked I was using more that 50% of the drive

Today when I switched to my usual id on the machine – I got a blue screen and when the system restarted the second drive was gone and when I looked at it with the windows disk manager is said the format is now “raw”

I been using the drive for backups – which can get quite large – im my case over 180gb – I don’t know if this caused the problem – but the best I can tell from the event log is that the drive was failing hours before a scheduled backup failed with i/o errors

Any help on how to get windows to find the true size of the disk would be appreciated - Thanks

Re: Windows can find drive size

Posted: 21 Oct 2018, 19:26
by cgrenier
Some External Enclosure hard drive case limit the capacity to 2 TB (or masks any bits higer than 2 TB).
Having been formatted, the filesystem will correctly until the 2 TB limit is hit. At this time, random corruptions occurs.
The correct disk capacity must be seen before trying to fix the filesystem.