Cisco Systems 3750E manual Understanding Auto-Upgrade and Auto-Advise

Chapter 5 Managing Switch Stacks

Understanding Switch Stacks

Understanding Auto-Upgrade and Auto-Advise

When the software detects mismatched software and tries to upgrade the switch in VM mode, two software processes are involved: automatic upgrade and automatic advise.

•The automatic upgrade (auto-upgrade) process includes an auto-copy process and an auto-extract process. By default, auto-upgrade is enabled (the boot auto-copy-swglobal configuration command is enabled). You can disable auto-upgrade by using the no boot auto-copy-swglobal configuration command on the stack master. You can check the status of auto-upgrade by using the show boot privileged EXEC command and by checking the Auto upgrade line in the display.

–Auto-copy automatically copies the software image running on any stack member to the switch in VM mode to upgrade (auto-upgrade) it. Auto-copy occurs if auto-upgrade is enabled, if there is enough flash memory in the switch in VM mode, and if the software image running on the switch stack is suitable for the switch in VM mode.

Note A switch in VM mode might not run all released software. For example, new switch hardware is not recognized in earlier versions of software.

–Automatic extraction (auto-extract) occurs when the auto-upgrade process cannot find the appropriate software in the stack to copy to the switch in VM mode. In that case, the auto-extract process searches all switches in the stack, whether they are in VM mode or not, for the tar file needed to upgrade the switch stack or the switch in VM mode. The tar file can be in any flash file system in the switch stack (including the switch in VM mode). If a tar file suitable for the switch in VM mode is found, the process extracts the file and automatically upgrades that switch.

The auto-upgrade (auto-copy and auto-extract) processes wait for a few minutes after the mismatched software is detected before starting.

When the auto-upgrade process is complete, the switch that was in VM mode reloads and joins the stack as a fully functioning member. If you have both StackWise Plus cables connected during the reload, network downtime does not occur because the switch stack operates on two rings.

Note Auto-upgrade performs the upgrade only when the two feature sets are the same type. For example, it does not automatically upgrade a switch in VM mode from IP services feature set to IP base feature set (or the reverse) or from cryptographic universal software image to noncryptographic universal software image (or the reverse).

•Automatic advise (auto-advise) occurs when the auto-upgrade process cannot find appropriate stack member software to copy to the switch in VM mode. This process tells you the command (archive copy-swor archive download-swprivileged EXEC command) and the image name (tar filename) needed to manually upgrade the switch stack or the switch in VM mode. The recommended image can be the running switch stack image or a tar file in any flash file system in the switch stack (including the switch in VM mode). If an appropriate image is not found in the stack flash file systems, the auto-advise process tells you to install new software on the switch stack. Auto-advise cannot be disabled, and there is no command to check its status.

The auto-advise software does not give suggestions when the switch stack software and the software of the switch in VM mode do not contain the same feature sets. For example, if the switch stack is running the IP base image and you add a switch that is running the IP services image, the auto-advise software does not provide a recommendation. The same events occur when cryptographic and noncryptographic images are running.

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

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