System information

Appendix
B-7
• Timely event notification
In addition to the audible alarm on the controller to alert the administrators, the firmware can also send out event notification
email and SNMP traps. To make sure that the events are delivered to the recipients, redundant servers are used to pass the
events. The administrator can also manually generate test events to see how events are logged and alerts are sent.
• Selective logging and notification
The firmware records a wide range of events, from informative events, like user login or management operations to critical
events, like power supply unit failure or RAID crash. To help find specific events in the log, the events are classified into
different severity levels and types. The administrator can choose the severity levels of events to be recorded, and different
event recipients can also be notified of events of different severity level.
B.11 Convenient Task Management
The RAID controllers are equipped with extensive utilities to support the system administrator to conduct maintenance tasks,
which may be to fortify the RAID protection by disk scrubbing, to reconfigure RAID attributes by migrating RAID level or stripe
size, or to expand LUN capacity. There are also other tasks like disk rebuilding or disk cloning that are started by the firmware
automatically. These tasks are done in the background and possess more or less performance impact to applications
accessing the storage system. To avoid the unwanted downgrade of service levels, the background tasks are required to be
manageable and the administrator needs to have the flexibility to control the tasks.
• Schedulable task execution
The administrator can schedule the background tasks with appropriate parameters to be started at a specific point of time,
which may be off-peak hours to avoid degrading the performance of the system. Without this function, the administrator might
be forced to run the task during business hours, or they have to wait till the end of business hours so as to execute the tasks
manually.
• Periodical task execution
Periodical schedule can be set for the maintenance tasks with appropriate parameters. This frees the administrator from
keeping records of when the tasks have been done and when to run the tasks again.
• Task execution logging and notification
Logs of task execution are recorded in the non-volatile memory on the controller, so that the administrator can easily track the
execution history of the tasks. The firmware also sends out notifications to inform the administrator about the current status of
the tasks; As a result, the administrator can easily monitor the progress, just like they are with the storage systems.
• Task progress monitoring and auto-resume
The firmware regularly provides the progress report of task execution as well as estimates when the tasks will be completed.
This helps the administrator to better plan the corresponding actions and manage the expectation of end users in the
organization. The progress is recorded on the hard disks, and if the storage system is restarted, either normally or
abnormally, the tasks will be automatically resumed at the point when the storage system is powered off.
• Disk-rebuild priority over maintenance tasks
There are chances that a disk might fail during the execution of maintenance tasks. To minimize the period of RAID
degradation, the maintenance task will be aborted or paused, and disk rebuilding will be executed immediately. This reduces
the risk of data loss and avoids unwanted performance impact. When the rebuilding is done, the paused tasks will be
automatically resumed.
• Task priority control
Executing the background tasks needs to occupy system resources, like CPU time, memory bandwidth, or access to disk
drive. The administrator can choose the priority of the background tasks to speed up the task execution or to prevent the task
from disturbing the host accesses. For more flexibility, the priority control is independently set for different types of
background task.