Back up the currently running software as follows:

• On the router, back up the currently running and active file system partitions to standby partitions that are not running. Specifically, the root file system (/) is backed up to /altroot, and /config is backed up to /altconfig. The root and /config file systems are on the router's flash drive, and the /altroot and /altconfig file systems are on the router's hard drive.
• On the switch, take a snapshot of the files currently used to run the switch—the complete contents of the root file system /, /config directory, and /var directory, which include the running Junos OS, the active configuration, and log files—and copy all these files onto an external drive. (If a USB flash drive is not connected, an error message is displayed.)

(TX Matrix and TX Matrix Plus router only) (Optional)

• all-chassis—On a TX Matrix router, archive data and executable areas for all Routing Engines in the chassis. On a TX Matrix Plus router, archive data and executable areas for all Routing Engines in the chassis.
• all-lcc—On a TX Matrix router, archive data and executable areas for all T640 routers (or line-card chassis) connected to a TX Matrix router. On a TX Matrix Plus router, archive data and executable areas for all T1600 routers (or line-card chassis) connected to a TX Matrix Plus router.
• lcc number—On a TX Matrix router, archive data and executable areas for a specific T640 router (or line-card chassis) that is connected to a TX Matrix router. On a TX Matrix Plus router, archive data and executable areas for a specific T1600 router (or line-card chassis) that is connected to a TX Matrix Plus router. Replace number with a value from 0 through 3.

(EX4200, EX4500, and EX8200 Virtual Chassis and MX Series routers only) (Optional) Specify where to place the snapshot (archive data and executable areas) in a Virtual Chassis:

• all-members—Create a snapshot (archive data and executable areas) for all members of the Virtual Chassis.
• local—Create a snapshot (archive data and executable areas) on the member of the Virtual Chassis that you are currently logged into.
• member member-id—Create a snapshot (archive data and executable areas) for the specified member of the Virtual Chassis.

(J Series routers only) (Optional) Create a snapshot that can be used to replace the medium in the primary compact flash drive. This option can be used on the removable compact flash only. The option copies the default files that were loaded on the primary compact flash drive when it was shipped from the factory, plus the rescue configuration if one has been set. This option is useful if you have multiple routers and want to use the same software and configuration on each router. After a boot device is created as a primary compact flash drive, it can operate in only a primary compact flash drive slot. This option causes the boot medium to be partitioned.

(J Series routers only) (Optional) Specify the size of the config partition, in megabytes. The default value is 10 percent of physical memory on the boot partition. The config partition is mounted on /config, and the configuration files are stored in this partition. This option causes the boot medium to be partitioned.

(J Series routers only) (Optional) Specify the size of the data partition, in megabytes. The default value is 0 MB. The data partition is mounted on /data. This space is not used by the router, and can be used for extra storage. This option causes the boot medium to be partitioned.

(J Series routers only) (Optional) Copy only default files that were loaded on the primary compact flash drive when it was shipped from the factory, plus the rescue configuration if one has been set. After the boot medium is created with the factory option, it can operate in only the primary compact flash drive.

(J Series routers and EX Series switches only)(Optional) Specify the boot device the software is copied to:

• compact-flash—Copy software to the primary compact flash drive.
• external—(Switches only) Copy software to an external mass storage device, such as a USB flash drive. If the media option is not specified, this is the default. If a USB drive is not connected, the switch displays an error message.
• internal—(Switches only) Copy software to an internal flash drive.
• removable-compact-flash—Copy software to the removable compact flash drive.
• usb—(M320, T640, MX960, and J Series routers only) Copy software to the device connected to the USB port.

(Optional) Repartition the flash drive before a snapshot occurs. If the partition table on the flash drive is corrupted, the request system snapshot command fails and reports errors. The partition option is only supported for restoring the software image from the hard drive to the flash drive.

(Routers only) You cannot issue the request system snapshot command when you enable flash disk mirroring. We recommend that you disable flash disk mirroring when you upgrade or downgrade the software. For more information, see the Junos OS System Basics Configuration Guide .

(EX8200 switch only) Specify where to place the snapshot in a redundant Routing Engine configuration.

• re0—Create a snapshot on Routing Engine 0.
• re1—Create a snapshot on Routing Engine 1.
• routing-engine routing-engine-id—Create a snapshot on the specified Routing Engine.

(J Series routers only) (Optional) Specify the size of the root partition, in megabytes. The default value is one-third of the physical memory minus the config, data, and swap partitions. The root partition is mounted on / and does not include configuration files. This option causes the boot medium to be partitioned.

(EX Series switches only) (Optional) Take a snapshot of the active root partition and copy it to the selected slice on the boot media.

(TX Matrix router only) (Optional) Archive data and executable areas for a TX Matrix router (or switch-card chassis).

(TX Matrix Plus router only) (Optional) Archive data and executable areas for a TX Matrix Plus router (or switch-fabric chassis). Replace number with 0.

(J Series router only) (Optional) Specify the size of the swap partition, in megabytes. The default value is one-third of the physical memory on a boot medium larger than 128 MB, or 0 MB on a smaller boot device. The swap partition is used for swap files and software failure memory snapshots. Software failure memory snapshots are saved to the boot medium only if it is specified as the dump device in the system dump-device configuration hierarchy. This option causes the boot medium to be partitioned.