From a support forum:
My issue is been resolved by following this article: EV100570
(My Disk is Read-only, Help!).
I find this happens intermittently as Windows Server Backup backs up a Hyper-V host and VSS creates temporary volumes. The volumes that error out are always the VSS volumes, and are gone by the time I can check it out. Host disk (array) is healthy, per Dell OMSA and CHKDSK. Not 100% confident there's no underlying problem, especially since this is a recent development.
The first step in troubleshooting this event is to make a backup of the data stored on the affected system. This should be followed by hard disk check (hardware utilities if available), chkdsk ran against the partitions, update of firmware for I/O controllers and hard disks, update of Windows and the applications installed. Any storage attached to the system (external disks, USB drives, cameras, scanners) may be related to the problem, so they should be disconnected during the troubleshooting process. In certain conditions, a corrupted pagefile may be the source of the problem so if possible, it should be moved to another drive and deleted from the original one.
If these steps fail to fix the problem, there might be a physical problem with one of the drives so it should be identified and replaced as soon as possible.