IBM System z10 EC Reference Manual page 36

Dynamic Oscillator Switchover
The z10 EC has two oscillator cards, a primary and a
backup. For most cases, should a failure occur on the pri-
mary oscillator card, the backup can detect it, switch over,
and provide the clock signal to the system transparently,
with no system outage. Previously, in the event of a failure
of the active oscillator, a system outage would occur, the
subsequent system Power On Reset (POR) would select
the backup, and the system would resume operation.
Dynamic Oscillator Switchover is exclusive to System
z10 EC and System z9.
Transparent Sparing
The z10 EC offers two PUs reserved as spares per server.
In the case of processor failure, these spares are used
for transparent sparing. On z10 EC sparing happens on
a core granularity rather than chip granularity as on z990
and z9 (for which "chip" equaled "2 cores").
Concurrent Maintenance
Concurrent Service for I/O features: All the features that
plug into the I/O Cage are able to be added and replaced
concurrent with system operation. This virtually eliminates
any need to schedule outage for service to upgrade the
I/O subsystem on this cage.
Upgrade for Coupling Links: z10 EC has concurrent
maintenance for the ISC-3 daughter card. Also, Coupling
Links can be added concurrently. This eliminates a need
for scheduled downtime in the demanding sysplex envi-
ronment.
Cryptographic feature: The Crypto Express2 feature
plugs in the I/O cage and can be added or replaced con-
currently with system operation.
Redundant Cage Controllers: The Power and Service
Control Network features redundant Cage Controllers for
Logic and Power control. This design enables nondisrup-
tive service to the controllers and virtually eliminates cus-
tomer scheduled outage.
Auto-Switchover for Support Element (SE): The z10
EC has two Support Elements. In the event of failure on
the Primary SE, the switchover to the backup is handled
automatically. There is no need for any intervention by the
Customer or Service Representative.
Concurrent Memory Upgrade
This function allows adding memory concurrently, up to
the maximum amount physically installed. In addition,
the Enhanced Book Availability function also enables a
memory upgrade to an installed z10 EC book in a multi-
book server.
Service Enhancements
z10 EC service enhancements designed to avoid sched-
uled outages include:
• Concurrent firmware fixes
• Concurrent driver upgrades
• Concurrent parts replacement
• Concurrent hardware upgrades
• DIMM FRU indicators
• Single processor core checkstop
• Single processor core sparing
• Point-to-Point SMP Fabric (not a ring)
• FCP end-to-end checking
• Hot swap of ICB-4 and InfiniBand hub cards
• Redundant 100 Mb Ethernet service network with VLAN
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