IBM Tivoli Storage Manager, Version 7.1

Data validation during audit volume processing

Data validation for storage pools allows the server to validate that data sent to a device during a write operation matches what the server later reads.

About this task

Data validation is helpful if you introduce new hardware devices. The validation assures that the data is not corrupted as it moves through the hardware, and then is written to the volume in the storage pool. You can use the DEFINE STGPOOL or UPDATE STGPOOL commands to enable data validation for storage pools.

When you enable data validation for an existing storage pool, the server validates data that is written from that time forward. The server does not validate existing data which was written to the storage pool before data validation was enabled.

When data validation is enabled for storage pools, the server generates a cyclic redundancy check (CRC) value and stores it with the data when it is written to the storage pool. The server validates the data when it audits the volume, by generating a cyclic redundancy check and comparing this value with the CRC value stored with the data. If the CRC values do not match, then the server processes the volume in the same manner as a standard audit volume operation. This process can depend on the following conditions:
  • The type of storage pool to which the volume is assigned
  • The FIX parameter of the AUDIT VOLUME command
  • The location of file copies (whether a copy of the file exists in a copy storage pool or an active-data pool)

Check the activity log for details about the audit operation.

The server removes the CRC values before it returns the data to the client node.



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