Dell Compellent Series 40 - Manual (Page 254)

246 Storage Center 5.5 System Manager User Guide
System Management
Alert Deletion
Alerts in the Indication and Alert History categories can be deleted. Once an alert is deleted,
it cannot be recovered.
Finding More Information About an Alert
Many alerts are associated with items that can be monitored in other areas of the System
Manager software. These items are displayed in the Object column. To see more
information about one of these objects, select the alert and then select the Show button in
the Alert Monitor toolbar.
For example, if you have an alert indicating that New Volume 1 is down, you can select that
alert, then select the Show New Volume 1 in System Explorer button. The System Explorer
will be brought forward and New Volume 1 will be selected.
Space Warnings
Conservation Mode
Storage Center enters Conservation Mode when remaining free space reaches 32 GB (or
less for systems smaller than 3.2 TB). When Storage Center enters Conservation Mode, the
system generates a Conservation Mode Alert to inform you that the system will not allow
new volumes to be created and that it will begin to aggressively expire Replays. The
Conservation Alert is close to the boundary where space is exhausted to keep these actions
from being performed unless necessary. Because of its proximity to the emergency
threshold, it is not a tool to manage storage, and should not be used to plan adding
additional disks to the system.
Emergency Mode
Emergency threshold means that the system can no longer operate because there is no
more free space. Storage Center:
• Generates an Emergency Alert
• Expires Replays early
• Will not permit new volumes to be created
• All volumes are taken offline
When Storage Center reaches the Emergency threshold, all server IO is rejected until the
system gets out of Emergency Mode. Because this is service affecting, special care should
be taken to monitor free space on the system to avoid reaching this threshold. Volumes will
not be able to be brought back online until enough space is freed to exit the emergency
state. Before a system reaches Emergency Mode, it is critical that you add space.