Starting in CTPOS 9.0R1, the compact flash contains two partitions each of which can have its own CTPOS version. If you use the dual image script, which comes with the CTPOS 9.0R1 upgrade package to create the two partitions, image1 will be the existing image (must be 7.1 or later) and image2 will be 9.0R1. However, there is another way to create a dual-imaged compact flash.

This article explains how to create a dual-imaged compact flash by using the alternative method.

A CTP flash image is available that will create a dual-imaged compact flash by using the dd command in Linux.

Note: The flash image is g-zipped on the Juniper download site and will occupy 4Gb of disk space after it is unzipped. So you need to make sure that you have at least that much space on the Linux server.

Perform the following steps to burn the CTPOS 9.0R1 flash image:

1. Go to the Juniper Software Download page and download the CTP flash_9.0R1.img.gz file from the Install Media software section.

2. Extract the g-zipped flash image file flash_9.0R1.img on any Linux system by using the following command:

gunzip flash_9.0R1.img.gz

3. Install the compact flash on a USB/compact flash adapter, and then install it on a Linux server. Make sure to note the device name when it mounts, for example: /dev/sda .

4. cd to the folder where the unzipped flash_9.0R1.img file resides.

5. Use the dd command to copy the image to the compact flash that is mounted on the Linux system. For example: 

dd if=flash_9.0R1.img of=/dev/sdc bs=1M << In this example, the compact flash is mounted as /dev/sdc.

6. When the dd command completes, install the compact flash on the CTP platform and power it up. You will notice that there are two 9.0R1 images when the grub loader screen appears.

7. Enter the first boot parameters (CTP default port, CTP name, and IP/mask) as you normally would after a flash reburn.

Note: It is not possible to "downgrade" one of the images to a 7.x release at this time.