EWF commands explained

Commands in the Windows Start->All Programs->ewf menu of a flash-based JACE-NXT are also available as “ewfmgr” commands in a console window, but shortcuts were added to the menu as a convenience for the most commonly used commands.

Figure 35. EWF commands in Windows Start menu on a Flash-based JACE-NXT

EWF commands in the Windows Start menu are described as follows:

Commit changes to C drive and leave protected - requires reboot

Executes the command ewfmgr c: -commit

Use case:
- When EWF (protection) is currently enabled on drive C, and
  - you have made changes to networking or other Windows configuration, even through Niagara tools (platform, PlatformServices, etc.), and you wish to persist the changes to flash.
  One example use case here is after adjusting the Windows firewall.
After executing this command, you must use the Reboot command. Changes are persisted only upon shutdown.
Commit changes to C drive and leave unprotected - requires reboot

Executes the command ewfmgr c: -commitAndDisable

Use cases:
- Before applying Windows security updates (NxtXpeUpdate file or files), where you also invoke the Reboot command. The, after applying all security updates, re-enable EWF (protection) on drive C and Reboot again.
- When EWF (protection) is currently enabled on drive C, and
  - you have made changes to networking or other Windows configuration, even through Niagara tools (platform, PlatformServices, etc.) and
  - you have additional changes you wish to make on drive C. Examples may include changes to Windows users or user groups, or changes to the Windows firewall.
  An example use case here is before the initial run of the Commissioning Wizard to commission a new JACE-NXT. You may still need to configure Windows users or user groups and/or adjust the Window firewall.
After executing this command, you must use the Reboot command. Changes are persisted only upon shutdown.
Following the reboot, and after completing other additional changes, remember to re-enable EWF (protection) on drive C and then reboot again!
Commit changes to E drive and leave protected - requires reboot

Executes the command ewfmgr e: -commit
Drive E is used by the Niagara station to store histories and logs. During normal operation, it is best to have executed this command, and then leave it without rebooting. Then, in the event the controller is rebooted, all of the history data accumulated in the overlay will be committed to flash storage. Thus, this should be the “normal” mode of operation for this partition.
Commit changes to E drive and leave unprotected - requires reboot

Executes the command ewfmgr e: -commitAndDisable
Drive E is used by the Niagara station to store histories and logs. You would normally not leave EWF disabled on this partition, unless directed to do so by technical support. Otherwise, excessive writes could damage the flash memory over time.
Discard changes to C drive and leave protected - requires reboot

Executes the command ewfmgr c: -nocmd

Use case:

When EWF (protection) is currently enabled on drive C, and any of the below:
- You have made changes to system configuration that you do not wish to keep.
  
  or
- The system volume (drive C) has been corrupted and/or compromise, perhaps by a virus.
After executing this command, you must use the Reboot command to discard the overlay data.
Any system config changes made since the last boot will be lost, so if you have changed user names or passwords, IP config, etc., be aware of this. The same result occurs if you have local access to a JACE-NXT with protection enabled for drive C, by simply turning the unit off and then back on.
Discard changes to E drive and leave protected - requires reboot

Executes the command ewfmgr e: -nocmd

After executing this command, you must use the Reboot command to discard the overlay data.
You would not normally exicute this command an reboot, unless directed to do so by technical support. Use may be necessary if there was obvious corruption to Niagara histories. Again, you get the same result if you have local access to a JACE-NXT with EWF enabled for drive E, by simply turning the unit off and then back on.
Enable protection on C drive - requires reboot

Executes the command ewfmgr c: -enable

Use this command to re-enable the EWF protection for the drive C System partition in flash memory. After executing this command, you must use the Reboot command for it to become effective.
Enable protection on E drive - requires reboot

Executes the command ewfmgr e: -enable

Use this command to re-enable the EWF protection for the drive E Histories partition in flash memory. After executing this command, you must use the Reboot command for it to become effective.
Protection Status

Executes the command ewfmgr -all

Leaving a command prompt window open to view the results, which include the current EWF state and next (boot) EWF command for both the E and C drive partitions.
In normal operation, for a stable, already-commissioned (deployed) JACE-NXT, a summary of the EWF status command should be similar to below:
- Device Name: [E], State: ENABLED, Boot Command: COMMIT
- Device Name: [C], State: ENABLED, Boot Command: NO_CMD
Reboot

Executes the command Shutdown -r -t 10

Which reboots the JACE-NXT controller in 10 seconds.