Install Vs. Bundle Mode

[config t]

What is the difference between install and bundle mode? Is there an advantage to using one over the other?

The first time I encountered this was while attempting to recover a switch that booted to rommon. After some troubleshooting I noticed there was no .bin file and instead a few .pkg and a packages.conf file that I had to boot to to make it work.

Is there a way to switch between the two modes? Eventually I will have to upgrade the IOS on these devices that are set to bundle mode and it seems all I can download from Cisco is the .bin

[SimonV]

I generally just upload the .bin file and change the boot variable. The only exception being when I need to upgrade a stack, then I run install mode because it takes care of all of the work.

[Dieselboy]

I encountered my first IOS-XE device last month and I was really confused how to upgrade the code on it. I couldnt get the install mode to work, the commands from the guide were not present on the device. I then just copied the image to the device, changed the boot var and rebooted while praying to the mythical Cisco-being. There were no issues with the device or the gui - however I couldnt get https working on it.

[config t]

I encountered my first IOS-XE device last month and I was really confused how to upgrade the code on it.

Good. It's not just me 

Well I did some diggin' around and found this link detailing 3850 Install vs. Bundle Mode:

https://content.cisco.com/chapter.sjs?uri=/searchable/chapter/c/en/us/td/docs/switches/lan/Denali_16-1/ConfigExamples_Technotes/Config_Examples/Misc/qos/m_install_vs_bundle.html.xml

I'm assuming, based on the paragraph below, that the two modes exist to speed up boot time. I haven't tested it because production network.

Also this:

The only exception being when I need to upgrade a stack, then I run install mode because it takes care of all of the work.

Information About Install Mode Versus Bundle Mode

Cisco Catalyst 3850 Series Switches have two modes of operation, Install and Bundle. Two or more switches must be in the same boot mode to form a switch stack.

The Install mode is the recommended mode for booting a switch.

Install Mode
The Install mode uses a package-provisioning file named packages.conf in order to boot a switch. In addition, there are a number of .pkg files in the flash drive. We recommend that you do not alter the packages.conf and .pkg files unless directed by a Cisco Technical Assistance Center (TAC) engineer.

Bundle Mode
The Bundle mode uses monolithic Cisco IOS images to boot a switch. The Bundle mode consumes more memory than the Install mode because the packages are extracted from the bundle and copied to RAM.