I'm running into a frustrating issue with Windows Server 2012 and VMWare ESXI.
I'm running ESXI version 6.5 (old I know, but this is not the issue) with a VM running Windows Server 2012. On this VM, I had a second disk (named windows2012-1.vmdk) attached as drive A: without any issue. I wanted to reinstall Windows Server 2012, so I powered off the VM, removed the windows2012-1.vmdk HDD via Actions -> Edit Settings -> and clicked the "x" next to the drive. I left the "Delete files from datastore" box unchecked. I then reinstalled Windows Server 2012 on the 40GB drive as a fresh install, not an upgrade. After this was done, I went back into Edit Settings to re-add the windows2012-1.vmdk file and it appeared to be added just fine via ESXI, however the disk is not showing up in the OS.
Disk Management does not show any disk other than the 40GB OS disk, and a rescan does not show the new drive. The drive does, however, show up in Device Manager as "VMware Virtual disk SCSI Disk Device" same as the 40GB one. Uninstalling/Reinstalling the driver does not work, nor does updating the driver. The windows2012-1.vmdk also appears to be recognized in the BIOS as well (although it doesn't have an OS on it so I can't boot from it).
Limitations, the windows2012-1.vmdk file is 5TB and I do not have any external HDDs to export it to for another month. I have the important files backed up (about 1TB of the 5TB) but do not have a backup of the other ~3.5TB.
Any thoughts as to why this might happen?