Digital Equipment EF5 Series, Руководство пользователя, Страница: 92 / 108

EF5XX Data Retention Description
Continuously
Saving Data
Unlike Digital’s earlier ESE20 and ESE50 solid state disks, the
EF5XX ISE continuously moves modified data to the internal
winchester disk drive. This minimizes the amount of data
that must be saved under battery power and ensures that the
data retention disk is still functional. Saving of data is a low
priority, background task that minimizes the effect of saving
data on performance.
Upon a power failure, the EF5XX instantly switches over to
battery power. Within one minute, firmware detects external
power has failed. Firmware then write-protects the EF5XX
ISE, preventing further data changes. Saving data to the
internal winchester (magnetic) disk drive continues under
battery power until all contents of the memory arrays are safely
on the winchester disk.
The EF5XX ISE then shuts itself off to conserve battery power.
Although continuously saving data dramatically decreases the
length of time to completely save final data, the fully charged
battery has sufficient power to completely save the contents of
the EF5XX to the winchester disk. While saving the data under
battery power, the yellow Write-Protect LED will be on and the
green Run/Ready LED will blink once per second.
Restoring
Data When power is restored, the EF5XX undergoes approximately
two minutes of power-on self-test (POST), which verifies the
integrity of the electronics and firmware.
After POST, the EF5XX is available for mounting and begins
restoring data to the memory arrays. While restoring data in
the offline state, the green Run/Ready LED blinks once per
second.
Continued on next page
5–2