# of controller chassis
configuration
Capacity of cache
memory module
Maximum cache capacity configurable based on
the number of cache path control adapter pairs
included:
1 cache path control
adapter pair (Included
with controller)
2 cache path control
adapter pairs (One
included with
controller and an
additional feature
added)
2.
HDS minimum cache per system is 64 GB whether configured with one or two controllers.
Item
Description
Item
Description
2 & 3
Main (required) cache path control
adapters
1 & 4
Optional cache path control adapters
1 & 2
Cluster 1
3 & 4
Cluster 0
Memory operation
The controller places all read and write data into the cache. The amount of
fast-write data in cache is dynamically managed by the cache control
algorithms to provide an optimum amount of read and write cache,
depending on the workload read and write I/O characteristics.
Data protection
The VSP G1000, VSP G1500, and VSP F1500 storage systems are designed to
protect the loss of data or configuration information stored in the cache when
electrical power fails. The cache is kept active for up to 32 minutes by the
cache backup batteries while the system configuration and data are copied to
the cache flash memory in the cache backup modules. For more information,
see
.
44
Introduction
Hitachi Virtual Storage Platform G1000, G1500, and Virtual Storage Platform F1500 Hardware Guide
