HP StorageWorks 12000, User Manual

Page: 119 / 266

NOTE:
Using oversubscription, you run the risk of running out of physical storage capacity and requires
careful planning of your storage needs and a review of your current storage policy.
Enabling and Disabling Oversubscription
To enable oversubscription:
In Command View VLS:
1. Select the System tab.
2. Select Chassis in the navigation tree.
The chassis details window opens.
3. In the Oversubscription section, select Enabled .
4. The Notify when storage capacity is [x] % Full box defaults to 90. You may change the value or
leave it at 90.
This percentage value is the threshold of storage space consumed that when reached triggers a
storage capacity notification alert. If this threshold is set to zero (0), an alert will be sent only
when existing capacity has been reached.
5. Click Apply Settings .
To disable oversubscription, deselect the Enabled box.
NOTE:
Oversubscription cannot be disabled while cartridge capacity is oversubscribed.
Shutdown at 98% Capacity
The system displays warnings on the Notifications screen when the backend storage capacity consumed
reaches the user-defined threshold (determined when you enabled oversubscription). Additional
notifications are sent when the capacity consumed reaches 95% and again at 98%.
At the level of 98%, the system will reject all attempts to write data from the backup application. Free
up storage space or add more storage before reaching this point to ensure that no data is lost. All
read operations remain unaffected.
Once you reduce the capacity consumed to a level below the user-defined threshold, writes from the
backup application resume automatically. However, if you reduce the capacity consumed to less than
98% but still above the threshold, you can manually resume writes by selecting
Enable Writes (now
visible) from the task bar of the Chassis status screen.
When the storage capacity consumed exceeds the user-defined threshold, the system:
• Displays warnings on the Notifications screen
• Sends emails (if configured) to specified users
• Sends alerts to the management consoles (if SNMP traps are configured)
• Displays the Reclaim Space link on the Chassis status screen
HP StorageWorks 119