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Configuring Automatic Mirroring of the CompactFlash Card on the Hard Drive

You can direct the device hard drive to automatically mirror the contents of the CompactFlash card. When you include the mirror-flash-on-disk statement, the hard drive maintains a synchronized mirror copy of the CompactFlash card contents. Data written to the CompactFlash card is simultaneously updated in the mirrored copy of the hard drive. If the CompactFlash card fails to read data, the hard drive automatically retrieves its mirrored copy of the CompactFlash card.


We recommend that you disable flash-to-disk mirroring when you upgrade or downgrade the router.

You cannot issue the request system snapshot command while flash-to-disk mirroring is enabled.

To configure the mirroring of the CompactFlash card to the hard drive, include the mirror-flash-on-disk statement at the [edit system] hierarchy level:


After you have enabled or disabled the mirror-flash-on-disk statement, you must reboot the device for your changes to take effect. To reboot, issue the request system reboot command.


This feature is not supported in Junos OS Release 20.1.