Upgrade 9500

[RRFS578780]

I'm going to upgrade the IOS, and I need what point of attention I should take before the activity.

Here are the current and new devices and versions:

C9500-16X
Current version: 16.9.3
New version: 17.03.03

C9200L-48T-4G
Current version: 16.12.04
New version: 17.03.04

I need to know if I can go straight to the new version and if there is anything to do or change before the upgrade.

[Leo Laohoo]

Direct upgrade, from 16.X.X, to 17.X.X is possible.  

IMPORTANT:  Please read the Release Notes carefully.

Please see attached document for a summarized version of the upgrade process.

[RRFS578780]

I found this, and was wondering if there's anything else to worry about upgrading.

• Upgrading the software image from Cisco IOS XE Gibraltar 16.12.x to any of the later releases can result in a persistent database operation failure and after which the persistent database cannot be restored.

  To avoid the persistent database operation failure, use the dir bootflash:.dbpersist command to list all DB persist files and then use delete bootflash:/.dbpersist/folder_name/file_name and bootflash:/.dbpersist/folder_name/file_name.meta commands to delete individual database and meta files from each persistent database folder.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9200/software/release/17-3/release_notes/ol-17-3-9200.html#id_67808

[Leo Laohoo]

That is from the 9200/9200L Release Notes.  
I do not have any experience managing this platform so I cannot make any comment about this.