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Verifying data on a medium – HP B6960-90078 User Manual

Page 158

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Managing Media

Verifying Data on a Medium

Chapter 4

128

Verifying Data on a Medium

What Is Verifying?

Verifying a medium shows whether the data on the medium is valid. It
also updates the information about the medium in the IDB, such as
medium condition.

Data Protector performs the following:

• Checks the Data Protector headers with information about the

medium (medium ID, description, and location.)

• Reads all blocks on the medium.

• If the CRC (Cyclic Redundancy Check) option was used while writing

to the medium, Data Protector recalculates the CRC and compares it
to the one stored on the medium.

If the CRC option was not used, and the verify operation passed, this
means that all the data on the medium has been read. The medium
did not cause a read error, so the hardware status of the tape is at the
very least acceptable. This level of check can be viewed as partial.

Additionally, if the CRC option was used, the backup data itself is
consistent within each block. This level of check has a high level of
reliability.

NOTE

Depending on the backup devices and media you use, this task can take a
considerable amount of time to complete.

When to Verify
Media

If errors were reported during backup, you can verify the medium to
check whether the backup is usable.

How to Verify Data
on a Medium

In the

Devices & Media

context, browse for a medium, right-click it, and

click

Verify

. For detailed steps, refer to the online Help index keyword

“verifying media”.