Data Safety - Compaq External RAID Controller & Subsystem Infortrend Operation Manual

Redundant Controller
Communication over
Fibre loops
No Single-point-of-
failure
Automatic engagement
of replacement
controller
Dynamic cache memory
allocation
Environment
management
Cache battery backup
Load sharing
User configurable
channel mode
Require a special
Firmware for redundant
controller?
Redundant Controller
rolling firmware upgrade
Redundant Controller
firmware
synchronization

Data Safety:

Regenerate Parity of
logical drives
Bad block auto-
reassignment
Battery backup for
cache memory
Verification on Normal
Writes
Verification on Rebuild
Writes
Firmware Functionality Specifications
Dedicated loops or distribution over drive loops selectable
Supported.
Supported in PowerPC series
Yes. Cache memory is dynamically allocated, not fixed.
Supported. SAF-TE, S.E.S., ISEMS (I
on-board controller voltage/temp monitor are all supported
in both single and redundant controller mode. In the event
of controller failure, serves can be taken over by the
existing controller.
Supported. Battery backup solutions for cache memory
are supported in both single controller and redundant
modes.
Supported. Workload can be flexibly divided between
different controllers by assigning logical configurations of
drives (LDs/LVs) to different controllers.
Supported. Channel modes configurable (SCSI or Fibre)
as HOST or DRIVE in both single controller and redundant
controller mode.
No. All firmware and all Infortrend external RAID
controllers support redundant controller function.
Firmware upgrade can be downloaded to the primary
controller and then be adopted by both controllers, without
interrupting host I/O.
In the event of controller failure, a replacement controller
running a different version of firmware can be combined to
restore a redundant system with a failed controller.
Different firmware versions can be auto-synchronized
later.
Supported. Can be performed every so often by user to
ensure that bad sectors do not cause data loss in the
event of drive failure.
Supported. Automatic reassignment of bad block
Supported. The battery backup solutions provide long-
lasting battery support to the cache memory when power
failure occurs. The unwritten data in the cache memory
can be committed to drive media when power is restored.
Supported. Performs read-after-write during normal write
processes to ensure data is properly written to drives.
Supported. Performs read-after-write during rebuild write
to ensure data is properly written to drives.
2
C interface); and
B-7