LUN Write Through Configuration

Procedure

1. Go to the Modify LUN dialog box.
   1. Log in to the ISM. In the navigation tree, choose All Devices > SN_XX > Storage Resources > LUNs, where SN_XX indicates a storage system.
   2. In the function pane, select the desired LUN.
   3. Click Modify.

      The Modify LUN dialog box is displayed.

2. Modify Write Policy of the LUN to Write Back/Mirroring. Table 1 describes the parameters for LUN properties.

   Table 1 Parameters for LUN properties

   Parameter	Description	Value
   Write Policy	Indicates the data write mode of a LUN.	Write Through: The storage system writes data onto the cache and disks on the storage system simultaneously upon receiving a data write request sent by the application server. Write Back/Mirroring: The storage system writes data onto the local and the peer cache simultaneously upon receiving a data write request sent by the application server. Write Back/No Mirroring: The storage system writes data only onto the local cache upon receiving a data write request sent by the application server. Write Back Mandatory/Mirroring: The storage system forcibly writes data onto the local and the peer cache simultaneously when encountering certain faults such as overheating or insufficient power supply from BBUs. Write Back Mandatory/No Mirroring: The storage system forcibly writes data onto the local cache when encountering certain faults such as overheating or insufficient power supply from BBUs.

3. Confirm the modification of properties for the LUN.
   1. Click OK.

      The Information dialog box is displayed indicating that the operation succeeded.

   2. Click OK. The properties for the LUN are modified.
4. If you have any questions, please contact technical support engineers for further handling.