Playback scenario (power lost or reboot)

If power is lost, a battery-less JACE is immediately off, with the last active SRAM block preserved by capacitor charge, plus typically one or more flash-preserved “.drdb” files. This could also occur if battery-equipped controller was unable to successfully complete an orderly shutdown. The JACE remains in this dormant state until power is restored, when the JACE boot process begins normally.
If a reboot command is given, the last active SRAM block is present, but typically no flash-preserved “.drdb” files—because a reboot typically first issues an “orderly shutdown”, starting with at station save. See “Station save effects” for details. The JACE boot process begins normally.
NOTE: A reboot issued from system shell is one exception—no orderly shutdown occurs before such a reboot. There may be .drdb files saved when this reboot happens. If so, these are “replayed” the same as if power is lost.

During station startup, after loading into DRAM the station’s last saved database (config.bog), the DataRecoveryService starts up and detects that recovered data exists in the preserved SRAM block, and also possibly in flash-preserved “.drdb” files.

The DataRecoveryService then performs the following actions:

It replays (writes to DRAM) all the flash files in sequence, beginning with the oldest.
Once flash records have been replayed, the service replays the records found in the SRAM block, as they are the most recent.

Note that in some cases this playback to DRAM can take a few minutes—this depends on how much data there is to replay. Station startup then completes, and an immediate save of the DRAM-restored station to flash (config.bog) occurs. All previous “.drdb” files are erased in flash, as well as SRAM data blocks, and DataRecoveryService operation begins anew. See “Recording (normal operation)” for details.

Playback scenario (power lost or reboot)

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