Windows 10 2004 glitch: Microsoft admits bug breaks Storage Spaces, corrupts files

Windows 10 users find a new glitch with certain configurations, missed by Microsoft in testing the latest feature update.

After Windows 10 upgrade, use this checklist to ensure safety and privacy

Microsoft has confirmed one more problem that could happen after installing Windows 10 version 2004: its RAID-like data-protection software, Storage Spaces, might malfunction. 

The company has warned Windows 10 users that they may see a compatibility hold on the Windows 10 2004 upgrade if Microsoft determines that their machine's configuration is impacted by the bug.

Storage Spaces is a feature of Windows and Windows Server that supports systems with multiple drives and lets users bundle up separate drives to create a pool of storage space and protect data from drive failures. 

SEE: Windows 10 May 2019 Update: 10 notable new features (free PDF) (TechRepublic)

"Devices using Storage Spaces might have issues using or accessing their Storage Spaces after updating to Windows 10, version 2004 (the May 2020 Update) and Windows Server, version 2004," Microsoft says in a new support note

"When using some configurations, partition for Storage Spaces might show as RAW in Disk Manager."

Microsoft advised against running the 'chkdsk' command on any device affected by this issue.

The new warning follows multiple reports about Storage Space issues last week on Microsoft's Feedback Hub, as reported by Windows Latest at the time

Users received multiple error reports when attempting to use the Storage Spaces management interface after installing the feature update.

Others reported seeing corrupted partitions and damaged files in Storage Spaces' parity spaces feature for storage efficient archiving. 

"My 20TB parity storage space shows up now as RAW, no accessible files. Storage Spaces tool and PowerShell show it as healthy, containing data. Looks like the ReFS partition has been corrupted, and I may have to fork out cash on recovery software and some external drives to copy files to so I can rebuild," one user wrote. 

"I started noticing corrupt photos I keep on my parity storage space in the last week. No errors in chkdsk though."  

Microsoft says there is no workaround for the issue but it does provide instructions for IT pros to set Storage Spaces to read only and block systems from writing to storage partitions. 

"Your device will still be usable, and any volume not seen as RAW should be readable," it notes. 

SEE: Microsoft to resume in July delivery of optional Windows 10 cumulative updates

Microsoft is investigating the issue and will provide an update when more information is available. It has not listed the issue on the known issues page for Windows 10 version 2004, which include various unresolved driver incompatibly issues.

Affected users can follow these instructions to marking locations as read-only:

  1. Select Start and type: powershell
  2. Right-click or long-press on Windows PowerShell and select Run as administrator.
  3. If prompted by a User Access Control dialog for Windows Powershell, select yes.
  4. Within the PowerShell dialog, type the following command and press enter: get-virtualdisk | ? WriteCacheSize -gt 0 | get-disk | set-disk -IsReadOnly $true
  5. Storage Spaces should now be set to read only, meaning you will not be able to write to them. Your device will still be usable, and any volume not seen as RAW should be readable.

More on Microsoft's Windows 10 May 2020 update