Installing the A6829A Adapter
Installing the A6829A Adapter
During an adapter replacement operation, SAM performs a Critical Resource Analysis (CRA), which checks all channels on the target adapter for critical resources that will be temporarily unavailable while the adapter is shut down.
Planning and Preparation
As mentioned earlier, for the most part, SAM prevents you from performing OLAR procedures that would adversly affect other areas of the
Critical Resources
Replacing an adapter that is still operating can have adverse consequences. As power to the slot must be off when the old adapter is removed and the new adapter is inserted, you must consider the effects of shutting down the adapter’s functions.
This is particularly important if no online failover or backup adapter to pick up those functions is installed. For example:
•Which mass storage devices will be temporarily disconnected when the adapter is shut down?
•Will a critical networking connection be lost?
A critical resource is one that would cause a system crash or prevent the operation from completing successfully if the resources were temporarily suspended or disconnected. For example, if the SCSI adapter to be replaced connects to the unmirrored root disk or swap space, the system will crash when the adapter is shut down.
During an OLAR procedure, it is essential to check the targeted adapter for critical resources, as well as the effects of existing disk mirrors and other situations where an adapter’s functions can be taken over by another adapter that will not be affected.
As mentioned earlier, SAM performs a thorough CRA automatically, and presents options based on its findings. If you determine that critical resources will be affected by the procedure, you could replace the adapter when the system is offline. On the other hand, if you are required to take an action immediately, you can use the rad command to try an online addition of a backup adapter and deletion of the target adapter.
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