AppSync: Mounts will fail when Cohesity is preventing lun removal on the AppSync Mount host.
Summary: Cohesity is preventing lun removal.
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This article does not apply to
This article is not tied to any specific product.
Not all product versions are identified in this article.
Symptoms
The Service Plan events will show the prior copy being unmounted successfully:
2022-08-30 04:56:24 Copy unmount completed successfully on mount host MountHost.
However Cohesity has prevented the removal of a device as seen in the MountHost System Event log, resulting in ghost devices existing on host:
08/30/2022 04:51:53 AM Warning MountHost.Hea 225 Microsoft-Windows-Kernel-PnP The application \Device\HarddiskVolume3\Program Files\Cohesity\cohesity_windows_agent_service.exe with process id 3824 stopped the removal or ejection for the device SCSI\Disk&Ven_EMC&Prod_Power&\{4A54205A-C920-4e28-88C5-9A6296A74B0B}&emcp&Power2079.
Which causes the mount to fail as seen here in the Service Plan Events:
2022-08-30 05:36:27 MountHost,Failed to mount volume P:\ because disk 514F0C545B600817 could not be found on the host after three attempts. Check the application and system event logs on the mount host for more information.
2022-08-30 05:36:27 AS-Server,VDS filesystem mount failed on host MountHost. See the host plug-in log and application event log for details.
2022-08-30 05:31:34 AS-Server,Performing cleanup on mount host MountHost after mount failure.
2022-08-30 05:31:34 MountHost,Canceling the VSS operation Mount after waiting 1800 seconds for Mount to complete.
2022-08-30 05:31:34 AS-Server,VSS volume import and filesystem mount failed on host MountHost. See the host plug-in log and application event log for details.
2022-08-30 05:26:30 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:21:27 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:16:23 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:11:18 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:06:14 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 04:59:52 AS-Server,Mounting file systems in read-write mode on mount host MountHost.
2022-08-30 04:59:50 AS-Server,Successfully enabled all snapshots.
2022-08-30 05:36:27 AS-Server,VDS filesystem mount failed on host MountHost. See the host plug-in log and application event log for details.
2022-08-30 05:31:34 AS-Server,Performing cleanup on mount host MountHost after mount failure.
2022-08-30 05:31:34 MountHost,Canceling the VSS operation Mount after waiting 1800 seconds for Mount to complete.
2022-08-30 05:31:34 AS-Server,VSS volume import and filesystem mount failed on host MountHost. See the host plug-in log and application event log for details.
2022-08-30 05:26:30 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:21:27 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:16:23 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:11:18 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 05:06:14 MountHost,The Mount operation is still in progress. You will be notified when the operation is complete.
2022-08-30 04:59:52 AS-Server,Mounting file systems in read-write mode on mount host MountHost.
2022-08-30 04:59:50 AS-Server,Successfully enabled all snapshots.
AppSync can not find the devices on the mount host in powermtdisplay output, and instead finds Pseudo name=harddisk??
The following will be found in the Mount host AppSync Plugin logs.
2022-08-30 05:01:04.988 INFO [22044] [] [MountHost] [xxx] Output of powermt display
2022-08-30 05:01:04.988 INFO [22044] [] [MountHost] [xxx] Output of powermt display Pseudo name=harddisk??
2022-08-30 05:01:04.988 INFO [22044] [] [MountHost] [xxx] Output of powermt display Pseudo name=harddisk??
The issue can be intermittent.
The number of luns on the host and number being unmounted/mounted can impact the frequency of the issue.
Seeing the issue every 2 weeks was the scenario this artcile was written for.
Cause
Cohesity is preventing the removal of luns on the host, leaving ghost devices on the host.
Resolution
Workaround:
Reboot the mount host to clear up the ghost devices devices left on the host due to Cohesity preventing removal.
Resolution:
Uninstall Cohesity on the Mount host or take other action so that Cohesity no longer prevents the removal of devices.
Reboot the mount host to clear up the ghost devices devices left on the host due to Cohesity preventing removal.
Resolution:
Uninstall Cohesity on the Mount host or take other action so that Cohesity no longer prevents the removal of devices.
Affected Products
AppSyncArticle Properties
Article Number: 000207176
Article Type: Solution
Last Modified: 15 Sep 2025
Version: 6
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