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Hardware and Software Considerations
PreScan and PostScan Batch Files
Hewlett Packard StorageWorks EVA 2.0 is a hardware-based snapshot engine and is used to create snapshots, which are then backed up by the iDataAgent. Because the backup does not occur on the production server, resources on the production server are not affected by this operation. The ProxyHost iDataAgent can be implemented into the HP StorageWorks EVA 2.0 environment to conduct backup operations using the data snapshot capabilities of EVA.
See ProxyHost - Application Support to see which operating systems and applications are supported for use with Hewlett Packard EVA 2.0 in conjunction with the ProxyHost iDataAgent.
The diagram that follows shows a sample configuration in an HP StorageWorks EVA 2.0 environment.
Data from the production server is distributed to virtual disks created on an HP StorageWorks EVA. During the backup the virtual disks will be snapped and the snapshot will be mounted to the backup host. All of these actions will be managed by a predefined HP StorageWorks EVA job which will be executed by the PreScan process.
During a ProxyHost backup, the following sequence of events takes place:
The following must be done before using ProxyHost with HP StorageWorks EVA 2.0.
The following must be installed on the production server:
The following must be installed on the backup host:
For more information and procedures, see Deployment - ProxyHost iDataAgent.
For CVSnaptool to successfully quiesce an Exchange server, the system’s PATH environment variable must be appended on the Exchange server to include the directory containing eseutil.exe, as follows:
<exchange_server_install_directory>\BIN
where <exchange_server_install_directory> is the full path and name of the Exchange install directory; for example:
C:\Program Files\Exchsrvr\BIN
ProxyHost in an HP EVA 2.0 environment is most commonly used to back up either snapshots or clones. Before each ProxyHost backup, the snapshots or clones must be created and mounted on to the backup host. These tasks are performed by an EVA job which will be called during the PreScan phase of each backup.
On the production server, you must create a PreScan batch file containing the appropriate evmcl command to initialize the EVA job. In order for the batch file to execute successfully, you must include the full path to the evmcl command.
The database Freeze/Thaw utility, CVSnaptool, will be implemented into the EVA job as the Suspend/Resume phase. This utility will ensure that the database and the transaction log remains consistent during the snapshot. Note that it is not necessary to quiesce the server for a file system backup with ProxyHost, and thus, no need of calling CVSnaptool from a pre-scan batch file.
It is recommended that you test the batch file before associating it with any subclients.
For specific configuration information on batch files for the PreScan and PostScan phases, see the Resource Pack for sample batch files and scripts.
We recommend that you test the batch file before associating it with any subclients.
To back up applications, such as Exchange 2000 or Exchange 2003 using ProxyHost, CVSnaptool is required; it is called from PreScan and PostScan batch files.
The use of CVSnaptool ensures that file system and application metadata remain unchanged, and therefore consistent, during the backup operation. Before creating the snapshot, the ProxyHost iDataAgent using CVSnaptool ensures that any supported applications have been ordered to flush buffered data and to suspend I/O to the disk. Once the snapshot has been created, the iDataAgent signals to the application that it may resume operations. Typically, the suspension of application I/O lasts only a few seconds. Custom scripts may be created to suspend and resume your applications. Sample scripts are provided on the Resource Pack.