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Example: Taking a Snapshot of the Software and Configuration

 

This example includes six scenarios in which you can take a snapshot of the currently running software and configuration on an ACX Series router, prior to the upgrade of an image or to remedy a bad image, thereby preventing the bad image from rendering the system useless.

Requirements

This example uses the following hardware and software components:

  • One ACX Series router

  • Junos OS Release 12.2 or later

Overview

In this example, the request system snapshot command is used to take a copy of the currently running software and configuration on another media—for example, a universal serial bus (USB) storage device, the active slice (da0s1 or da0s2) of a dual-root partitioned router, or the alternate slice (da0s1 or da0s2) of a dual-root partitioned router. A snapshot to another media ensures that the device can boot from the other media in case the system does not boot up from the current image.

Caution

After you run the request system snapshot command, you cannot return to the previous version of the software, because the running and backup copies of the software are identical.

Taking a Snapshot

Scenario: To take a snapshot from a NAND flash device slice to a USB storage device:

  1. Boot up the router from the NAND flash device and make sure that a formatted USB storage device is plugged in to the router’s USB port. The USB storage device must be formatted for the root (/) and /config directories.
  2. Issue the request system snapshot command.
    user@host> request system snapshot

    The root (/) and /config directories from the currently mounted NAND flash slice are copied to the USB storage device.

Scenario: To take a snapshot from a NAND flash device slice to a USB storage device with formatting:

  1. Boot up the router from the NAND flash device and make sure that a USB storage device is plugged in to the router’s USB port. Note

    Formatting a USB storage device deletes all the data on the USB storage device.

  2. Issue the request system snapshot partition command.
    user@host> request system snapshot partition

    After the USB storage device is formatted, the root (/) and /config directories from the currently mounted NAND flash slice are copied to the USB storage device.

Scenario: To take a snapshot from the active slice of the NAND flash device to the alternate slice:

  1. Boot up the router from the NAND flash device.
  2. Issue the request system snapshot slice alternate command.
    user@host> request system snapshot slice alternate

    The root (/) and /config directories from the currently mounted NAND flash slice are copied to the other slice.

Scenario: To take a snapshot from an active slice of the NAND flash device to the alternate slice after partitioning:

  1. Boot up the router from the NAND flash device.
  2. Issue the request system snapshot partition slice alternate command.
    user@host> request system snapshot partition slice alternate

    The BSD label (disk partitioning information) for the active flash slice is installed and then the root (/) and /config directories from the currently mounted NAND flash slice are copied to the other slice.

Scenario: To take a snapshot from a USB storage device to the active slice of the NAND flash device:

  1. Boot up the router from a USB storage device containing the required Junos OS image.
  2. Issue the request system snapshot command.
    user@host> request system snapshot

    The root (/) and /config directories from the USB storage device are copied to the active NAND flash slice.

Scenario: To take a snapshot from a USB storage device to the active slice of the NAND flash device after partitioning:

  1. Boot up the router from a USB storage device containing the required Junos OS image.
  2. Issue the request system snapshot partition command.
    user@host> request system snapshot partition

    The BSD label (disk partitioning information) for the active flash slice is installed and then the root (/) and /config directories from the USB storage device are copied to the active NAND flash slice.