User Manual - A3661-90001

Single-System Distance Topology 2-11
Hardware Topologies
Table 2-2 Single-System Distance Topology Error Recovery
Failing
component
Continue
after failure? What happens and how to recover
Disk module Yes Applications continue to run on all supported RAID levels (RAID-1, 1/0,
3, and 5). The system administrator or service provider hot-replaces
the failed disk module.
SP in single-
SP array (no
high
availability)
No The disk array fails. The system administrator or service provider
replaces the SP and the system administrator restarts the operating
system and applications.
SP in dual-SP
disk array
No on path to
failed SP;
Yes on alternate
path through
second SP
Ownership of the failed SP’s LUNs can transfer automatically to the
remaining operational SP if primary and alternate paths have been
configured in LVM. If so, LVM switches automatically and transparently
to the alternate path. The system administrator or service provider hot-
replaces the failed SP.
Fan pack Yes Applications continue to run. The system administrator or service
provider hot-replaces the fan pack.
Power supply
unit
Yes if three power
supply units;
No if two power
supply units (no
high availability)
If three power supply units are present, applications continue to run
when one power supply unit fails. The system administrator or service
provider hot-replaces the failed power supply unit.
If two power supply units are present, the disk array fails. The system
administrator or service provider replaces the failed power supply unit
and the system administrator restarts the operating system and
applications.
HP FC-AL
Hub
No No I/O operations are possible between the host and any disk arrays
because all I/O traffic is routed through the HP FC-AL Hub. The
authorized service provider replaces the failed HP FC-AL Hub and the
system administrator restarts the operating system and applications.
FC I/O
adapter
No on path to
failed adapter;
Yes if array has
dual SPs and
alternate paths
have been
configured
I/O operations fail along the path through the failed adapter. If the host
has two FC adapters connected to a dual-SP disk array, the array can
be accessed through the path to the operational adapter and SP if
primary and alternate paths have been configured in LVM. If so, LVM
switches automatically and transparently to the alternate path. The
authorized service provider replaces the failed adapter and the system
administrator restarts the operating system and applications.
FC cable No on path to
failed cable;
Yes if array has
dual SPs and
alternate paths
have been
configured
I/O operations fail along the path through the failed cable. If the host
has two FC adapters connected to a dual-SP disk array, the array can
be accessed through the operational path if primary and alternate paths
have been configured in LVM. If so, LVM switches automatically and
transparently to the alternate path. The authorized service provider hot-
replaces the failed cable.