HP StorageWorks TapeAssure service version 1.1 User guide (EH957-90925, September 2010)

Conducting a utilization assessment for tapes
Tape utilization is an assessment of the efficiency of tape use.
1. To view tape utilization data from the TapeAssure tab, select Tapes > Utilization from the navig-
ation pane.
Utilization is shown under the column: Capacity used (at last sample) along with two other
measures: Data Write and Data Read (in sample time).
2. Tape capacity used is shown as a percentage (different cartridge types have different absolute
capacities) and is the capacity used at the time of the last sample.
With all your tapes listed in a table, it is quick to compare across all your tapes. If capacity used
is lower than expected, you may be able to adjust your backup jobs to make more efficient use
of your tapes.
• The Data Written and Data Read columns show how much data was written or read during
the sample period, which shows how much use or re-use of the tapes were made in that
period.
3. To change the sample time, click on the Actions pull-down list.
4. Select the desired sample time and click OK.
Conducting a utilization assessment
The overall figure for drive utilization is calculated by multiplying the performance achieved (as a
percentage of the drive’s maximum native rate) by the time based utilization. For example:
• An HP LTO-4 Ultrium 1840 has a maximum native media rate of 120 MB/s. If the actual native
rate achieved is 30 MB/s, that is a performance achievement of 25%.
• If the time based utilization shows 20%, combining these together gives you an overall utilization
of 20% x 25% = 5%. These are typical figures showing just how much potential extra utilization
is available.
Note that assessing overall utilization is currently a manual process and not shown directly in the HP
TapeAssure user interface.
About email alerts
Command View TL enables you to set up and receive email alerts about any performance or utilization
data. For more information, see the HP StorageWorks Interface Manager and Command View TL
user guide. Although not covered in this document, alerts are an extremely valuable part of TapeAssure
because they provide hands off monitoring of your tape drives and tapes.
Using TapeAssure24