With versions 11.26 or 11.28, if ransomware protection is enabled backups may fail and disk libraries hosted on a UNC path may go offline

When upgrading to 11.26 or 11.28 with ransomware protection enabled, or when enabling ransomware protection on these versions, backups may fail and/or disk libraries or mount paths hosted using a UNC path may go offline.

Symptoms

• Backups may fail when accessing the index cache when Ransomware protection is enabled on MediaAgent. The error may be similar to "CreateIndex failure; please check CreateIndex.log file on MediaAgent"
• Library mount path may show offline after Ransomware protection is enabled for a UNC path

On the Media Agent hosting the index an/or UNC mount path, you may see the following errors in the DlpAlerts.log log file on the Media Agent

### ALERT: BlockOpen [\?\Volume{0000000-0000-0000-0000-000000000000}\IndexCache\CV_Index\...\ScanInfoTot.cvf], ImageName [\?\Volume{a726834a-0000-0000-0000-501f00000000}\Program Files\Commvault\ContentStore\Base\cvd.exe], AccountName [NT AUTHORITY\SYSTEM], CreateDisposition [0x5]
### ALERT: BlockOpen [\?\Volume{0000000-0000-0000-0000-000000000000}\IndexCache\CV_Index\...\ScanInfoTot.cvf], ImageName [\?\Volume{a726834a-0000-0000-0000-501f00000000}\Program Files\Commvault\ContentStore\Base\cvd.exe], AccountName [NT AUTHORITY\SYSTEM], CreateDisposition [0x5]
### ALERT: BlockOpen [\?\Volume{0000000-0000-0000-0000-000000000000}\IndexCache\CV_Index\...\ScanInfoTot.cvf], ImageName [\?\Volume{a726834a-0000-0000-0000-501f00000000}\Program Files\Commvault\ContentStore\Base\cvd.exe], AccountName [NT AUTHORITY\SYSTEM], CreateDisposition [0x5]

Resolution

Maintenance release updates are available to resolve this issue, which can be obtained from the Commvault store. Use the table below to identify the right maintenance release version to install: