High Reliability; High Flexibility - Hitachi G1500 Hardware Manual

High reliability

The storage system includes the following features to enhance reliability:
Multiple RAID configurations: The system supports RAID 6 (6D+2P and 14D+2P),
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RAID 5 (3D+1P and 7D+1P), and RAID 1 (2D+2D and 4D+4D).
Duplicate hardware: Every module in the controller chassis and drive chassis is
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configured in redundant pairs so that if any module fails, the redundant module takes
over until the failed component is replaced. The redundant hardware includes power
supplies, VSD pairs, cache path controllers, front-end directors, back-end directors,
and drives. If one of these hardware components fails, the storage system continues
normal operation with zero data loss.
Protection from power failures: The storage systems have dual-power feeds. In the
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event of a partial power loss on one of the feeds, the system operates normally on
the alternate feed until full power is restored. In the event of a full power loss, the
cache backup modules maintain the availability of the cache contents for 32 minutes
while the system copies the system configuration information and all data in the
cache to a cache flash drive (SSD).

High flexibility

The storage systems are available in several configurations, from a small single rack,
diskless system to a large six-rack system that includes two controller chassis, up to
2,304 SFF drives, up to 1,152 LFF drives, up to 384 SSDs (per controller in a standard
performance back-end configuration) or 1,152 SSDs (per controller in a high-
performance back-end configuration), up to 576 flash module drives, and a total of 2 TB
cache. The systems can be easily reconfigured for more storage capacity.
The storage systems support block-only, file-only, and unified (block and file)
configurations in open and mainframe environments. Unified systems contain Hitachi
Network Attached Storage servers and switches in addition to the block controller and
storage drives.
Chapter 1: VSP G1000, VSP G1500, and VSP F1500 overview
Hitachi Virtual Storage Platform G1000, G1500, and VSP F1500 Hardware Guide
High reliability
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