Establishing the OS image library
The OS Image library stores binary images by vendor for use on the Deploy OS Image action. Each branch in the library represents a unique OS image. Branches are created when you pre-stage a new image for deployment or when BMC Network Automation detects a new OS version during a configuration snapshot. Each branch contains an OS image binary file that is added when one of the following occurs:
- You manually add the binary when pre-staging a new image.
- You perform a Snapshot OS Image action. This forces BMC Network Automation to copy the binary from the device to the library.
- You perform a Deploy OS Image when the device's current OS binary is not currently stored for the branch. BMC Network Automation copies the binary from the device to the library. This ensures the current binary is available for rollback. This feature is available for devices that support the Snapshot OS Image action. In addition, if a user loads a binary from the file system directly during the Deploy OS Image, the binary is automatically stored in the library.
OS images added to the OS image library must be <= 1GB. Also, the same limit applies to OS images included as files in the Deploy OS Image span actions.
After initial software installation, BMC recommends copying binaries that are currently deployed in the network to the library by using the Snapshot OS Image span action. This ensures optimum performance when deploying a new image to a device for the first time. BMC Network Automation skips saving the current binary for rollback when it detects that the image is already stored in the library.
You can use the following tips and tricks when running the initial Snapshot OS Image span action. When a group or realm is selected as the network span, you have the option of running the Snapshot OS Image action serially or in parallel.
- If the selected devices only have a few different OS image versions, you should run the Snapshot OS Image action serially for best performance. Otherwise, BMC Network Automation might copy the same image multiple times from each device to BMC Network Automation.
- If the selected devices have several different OS image versions, you should run the Snapshot OS Image action in parallel for best performance. The best performance is achieved when each device in the group has a different OS image version.
- You might want to create a static group of devices that represent the different OS image versions running in the network, and then run the action in parallel. This approach stores all production images into the OS Image Library with one request.
You can add a branch and its associated binary to the library to pre-stage a new image for the Deploy OS Image action. When adding a new image, BMC recommends that you enter the vendor supplied message digest (MD5), memory footprint and activation key, as applicable.