Fault masking

If corrections and retries succeed and do not exceed threshold limits, the system remains operational with full resources and no client or IBM Service Representative intervention is required.

Resource deallocation

If recoverable errors exceed threshold limits, resources can be deallocated with the system remaining operational, allowing deferred maintenance at a convenient time.

Dynamic deallocation of potentially failing components is non-disruptive, allowing the system to continue to run. Persistent deallocation occurs when a failed component is detected; it is then deactivated at a subsequent reboot.

Dynamic deallocation functions include:

￿Processor

￿L3 cache lines

￿Partial L2 cache deallocation

￿PCI-X bus and slots

Persistent deallocation functions include:

￿Processor

￿Memory

￿Deconfigure or bypass failing I/O adapters

￿L3 cache

Following a hardware error that has been flagged by the service processor, the subsequent reboot of the server invokes extended diagnostics. If a processor or L3 cache has been marked for deconfiguration by persistent processor deallocation, the boot process will attempt to proceed to completion with the faulty device automatically deconfigured. Failing I/O adapters will be deconfigured or bypassed during the boot process.

Concurrent Maintenance

Concurrent Maintenance provides replacement of the following parts while the processor complex remains running:

￿Disk drives

￿Cooling fans

￿Power Subsystems

￿PCI-X adapter cards

4.3Hypervisor: Storage image independence

A logical partition (LPAR) is a set of resources on a processor complex that supply enough hardware to support the ability to boot and run an operating system (which we call a server). The LPARs created on a DS8000 processor complex are used to form storage images. These LPARs share not only the common hardware on the processor complex, including CPUs, memory, internal SCSI disks and other media bays (such as DVD-RAM), but also hardware common between the two processor complexes. This hardware includes such things as the I/O enclosures and the adapters installed within them.

66DS8000 Series: Concepts and Architecture

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IBM DS8000 manual Hypervisor Storage image independence, Fault masking, Resource deallocation, Concurrent Maintenance