IOS XE boot command behavior

[KyleBading]

I have a WS-C6509-E running IOS 12.2(33)SXJ10 and I am upgrading to a C9300-48S running IOS XE 17.9.4a. What is the behavior of the boot system disk command and can this be replicated on the 9300? Also, are boot-start-marker/boot-end-marker necessary?

boot-start-marker

boot system disk0:s72033-ipservicesk9_wan-mz.122-33.SXJ10.bin

boot system disk0:

boot-end-marker

Thanks,

KB

[Flavio Miranda]

@KyleBading 

   Boot-start/end is not necessary in IOS-XE and the command boot will depend on the mode you are going to use: Install mode or Bundle mode.

For install mode you can use

boot system bootflash:packages.conf

For bundle mode

boot system bootflash:<new filename>

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9300-series-switches/216231-upgrade-guide-for-cisco-catalyst-9000-sw.html

[Leo Laohoo]

In addition to @Flavio Miranda, I would like to share a word of "caution" about using 17.9.X because the entire 17.9.X should be called "Train Wreck" (and not "Cupertino"). 

We have dumped 17.9.X and migrating to 17.12.3/17.12.4.  

Finally, IOS and IOS-XE are different beasts.  One is designed for stability over a long period of time (decades) and the other requires frequent reboots.  Always monitor the control-plane memory utilization of all routers, switches, WLC that run on IOS-XE daily.  Normal memory utilization should not exceed 45%.  If the memory utilization is >50% that's trouble.  If the memory utilization is >70% be prepared to intervene.