Cybernetics miSAN-V6, Operator'S Manual

Page: 128 / 190

128 Using the 3ware Disk Manager®
Cybernetics UM-MV-86-B1-0801
About Task Schedules
Each type of task may be scheduled for up to seven times per week. This limits active ini-
tializing, rebuilding, verifying, and testing of a unit to the times you specify, so that the
task does not interfere with peak I/O times.
If all seven schedule slots are filled, you must first remove one or more schedule times
before you can add another.
You may set schedule times whether scheduling is set to be followed or ignored. This is
useful if you want to temporarily disable the schedule.
If you remove all the schedule times for a particular background task, initializations and
rebuilds will run anytime, as they are needed. Verify will only run if started by the CLI or if
the Verify Unit button is clicked.
About Self-tests
Unlike scheduling of rebuilds and verifies, scheduling of self-tests is always followed. To
disable self-tests you either remove all schedule times, or uncheck the tests listed in the
Tasks column.
Two self-tests can be scheduled:
• Upgrade UDMA mode : This test checks the speed at which data transfer to drives is
occurring, to see if the UDMA mode can be increased. (If you are already running at
the fastest UDMA mode, then this self-test has no effect.)
The UDMA mode can become downgraded in the event that cable CRC errors are
encountered, requiring multiple retries to read sectors. In severe cases, the UDMA
mode may be downgraded from ATA 150 to ATA 133, to ATA 100, to 66, to 33.
This check is also done every time the system is booted. UDMA mode does not apply
to SATA.
• Check SMART Thresholds : This test checks to see whether SMART thresholds
have been exceeded.
The SMART thresholds indicate when a drive is likely to fail, based on the number of
errors that have been recorded through SMART (Self-Monitoring, Analysis and
Reporting Technology).