HP StoreEver TapeAssure Software User Manual
Page 104
In L&TT 4.12 the LTO drive assessment test was improved to be more accurate and consistent while
also making a pass/fail decision with a single tape. This section describes the operation of the
test so you can understand how it works and gain confidence in its assessment of the drive.
The test contains four main sections:
•
Analyze the drive logs. The test pulls over 60 logs from the drives and analyzes them with
about 20 rules and 130 sub-rules. Any issues considered critical in a support ticket, which
uses the same rules, will cause the test to fail the drive at this point. Other issues, such as
cleaning requests or the detection of host polling, will be noted in the test output for
informational purposes.
•
Test the load/unload mechanism. The cartridge is unloaded, partially ejected, and reloaded.
Any potential mechanical failures are flagged.
•
Run error rate tests. The test runs a series of internal error rate tests at different speeds and
different tape directions. This the core of the assessment test.
•
Clean up. The error rate tests leave the cartridge in an 'invalid' state, which is reset with a
short erase process.
Error rate tests
The error rate tests are a series of short tests at a variety of tape speeds in both directions. A typical
test will perform 60–70 individual error rate tests and each one will check error rate margin,
variations across all the heads, and accuracy following tracks. This approach allows for:
•
Characterization of drive error rate by tape speed
•
Characterization of drive error rate by direction (forward and reverse)
•
Filtering out areas of bad tape, which allows the test to run using a single tape
The error rate tests cycle through a series of tape speeds, as shown in
. Half of the tests
are written in the forward direction and the other half are written in the reverse direction. This
ensures that both sets of heads are tested, as well as the full range of tape speeds.
Figure 43 Cycling through a series of tape speeds
The error rate tests for each tape speed will occur at different places in the tape and in different
directions, as shown in
. This allows the test to characterize the drive for that tape speed.
104 Tests and utility functions