A device tree is a data structure that describes the LUNs in your environment. When you remove LUNs dynamically from an existing target ID, the operating system SCSI device tree must be cleaned up. This is to release the SCSI target ID for reuse if a new LUN is added to the host later. In Storage Foundation/InfoScale, there are two ways to do this: one if you are using Storage Foundation and High Availability (SFHA) version 6.0 or earlier you must clean up the device tree manually. In SFHA 6.0.1 and later, the device tree is cleaned up dynamically.
For SFHA 6.0 and earlier
For SFHA 6.0 and earlier, you need to clean up the operation system device tree manually after you remove LUNs from an existing target ID. To completely remove LUNs from an existing target ID, you need to perform the following steps:
The following diagram shows the process of removing LUNs dynamically from an existing target ID.
For SFHA 6.0.1 and later, and InfoScale
Since SFHA 6.0.1, the Dynamic Reconfiguration operations option (DR tool) is introduced in the vxdiskadm menu to simplify the removal of LUNs from an existing target ID. It saves the manual work of device scanning and cleaning up. Through the DR tool, Dynamic Multi-pathing (DMP) updates and cleans up the operating system device tree automatically.
For more information about using DR tool to remove LUNs, please see: Removing LUNs dynamically from an existing target ID.
The following diagram shows the process of using DR tool to remove LUNs dynamically from an existing target ID. The process is simplified by using this tool.
The links in this article are specific to Linux platform. You can find SFHA Solutions/InfoScale documents for other versions and platforms on the SORT documents page.