TB031 Windows Targets May Fail to Reestablish iSCSI Connections with the Delphix Engine
Alert Type
Data Availability
Impact
If the existing iSCSI connection between a Windows host and the Delphix Engine is lost due to a network issue or a Delphix engine reboot, the Windows host may fail to reestablish an iSCSI connection to the Delphix engine. MS SQL Virtual databases (VDBs) and/or virtualized files (vFiles) hosted on these hosts will be unavailable as a result. If the target server is used as a staging environment, staging databases will also be unavailable.
If the iSCSI connection were lost due to a Windows host reboot, the iSCSI connection will be successfully reestablished if the host has VDBs. This reestablishment is done as part of the VDB restart logic following a Windows host reboot.
Contributing Factors
The issue may occur in the following Delphix Releases:
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Delphix Engine 4.2.3.0
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Delphix Engine 4.2.4.0
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Delphix Engine 4.2.5.0 and 4.2.5.1
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Delphix Engine 4.3.1.0
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Delphix Engine 4.3.2.0 and 4.3.2.1
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Delphix Engine 4.3.3.0
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Delphix Engine 4.3.4.0 and 4.3.4.1
- Delphix Engine 4.3.5.0
It may also occur in the following releases if the engine was upgraded from any of the above releases. New installations of these versions are not impacted:
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Delphix Engine 5.0.1.0 and 5.0.1.1
- Delphix Engine 5.0.2.0 and 5.0.2.1 and 5.0.2.2 and 5.0.2.3
The problem can only occur when using SQL Server VDBs or virtualized files (vFiles)
Symptoms
The iSCSI connection with the Delphix engine will be in an "Inactive" state. All associated VDBs and staging databases will be down.
Relief/Workaround
Prior to Delphix Engine version 4.3.3.0, the following steps should be done:
- Remove the Delphix iSCSI target from "Favorite Targets" using the iSCSI Initiator program on the Windows host.
- Refresh the affected target environment from the Delphix engine. This will reestablish the connection.
From Delphix Engine 4.3.3.0 onwards, a case to Delphix Support is required to help reestablish the iSCSI connection.
Resolution
The issue is fully resolved in Delphix Engine 5.0.3.0, and later releases.