Use DISKPART to bring a disk online
If you’ve recently migrated a VMWare Fusion virtual machine to VMWare ESXi, which itself had multiple disks, you may find that secondary disks don’t show up. You can change this using DISKPART.
In my case, this didn’t happen in a Windows 10 VM with two disks, but did happen in Windows Server 2016 with two disks.
Anyway, it’s reasonably easy to fix, using DISKPART.
- Open a CMD prompt and type DISKPART
- You should got a ACL type auth warning, just OK It
- This will open a new console window with DISKPART> prompt
- Type LIST DISK
- You should see your various disks listed, and one (or more) will be Offline
- Type SELECT DISK 1
- Type ONLINE DISK
- At this point, your disk should appear in Windows Explorer
- If you find you cannot create anything on the disk, then it’s possible it’s readonly, in which case
- Type ATTRIB DISK CLEAR READONLY
That should be everything you need.