Hitachi F400 Hardware Reference Manual page 60

Cache specifications
Capacity (GB)
NAS module Cache Capacity
Control method
Battery backup
Backup duration
Data in the cache memory is preserved against power failures. If a power
outage occurs, data in cache memory is written to drives.
When the storage system enters Cache Backup mode, the amber WARNING
LED goes on to when the system starts. This warning indicates that the
battery charge has dropped significantly and the remaining battery capacity
is not sufficient; the storage system will continue operating with the Write
Cache function disabled.
When the battery is charged, the warning indication disappears, and the
storage system continues the operation in the Write Cache function.
The warning indication disappears within six hours. Even when the warning is
shown, normal operation is assured in Write-Through. Read and write
performance is lowered because the Write Cache function is disabled.
If the storage system is not charged for more than six months, the battery
can become overcharged and sustain unrecoverable damage. To avoid this
situation, charge the battery more than 3 hours every six months.
Insulation performance
Insulation withstand voltage
Insulation resistance
60
Item
Item
Mechanical specifications for VSP F400, F600
Hitachi Virtual Storage Platform F400, F600 Hardware Reference Guide
Specification
VSP F400: 128
VSP F600: 256
DDR3 DIMM 8GB x 12 [Slot]
Note:
• All 12 slots must be fully installed with
DIMMs.
• Each DIMM is replaceable when they fail.
• The DIMM is not common and cannot be
used with DKC DIMM.
Read LRU, Write after
Provided
Unrestricted (saving to a nonvolatile memory)
Specification
AC 1,500 V (100 mA, 1 min)
DC 500 V, 10 M Ω or more