Decommission SharePoint 2013 on-prem after migration

Question

This was my first migration where I migrated site to SP online from SP2013.

Now all site collections are migrated and I am asked to decommission old SP2013 server.

Please help with official steps to decommission SP2013 server.

Answer 1

There is no "official" way to decommission SharePoint 2013. Also, it is unclear what you mean exactly by decommissioning.

Suggested Decommission Steps

• Set SharePoint 2013 Site collections to ReadOnly Set-SPSite SITE_URL -LockState ReadOnly command.
• Perform migration. It is assumed you have already done your migrations and that you already set your 2013 sites to ReadOnly. Otherwise, there is a good chance at least some users keep uploading and changing documents there. If you missed this step, you might need to set your site to ReadOnly immediately and assess the damage before you continue any further.
• Lock SharePoint 2013 Site collections using Set-SPSite SITE_URL -LockState NoAccess command.
• Take backups of your SharePoint Content Databases.
• Prepare a recovery plan. Make sure the plan includes steps on how to 1) restore the farm 2) restore content databases and 3) extract data (documents) in case someone requests them.
• Wait for a few weeks/months. The idea is to determine if there were any users still working with the legacy SP 2013 after migration. You'll know if that's the case when users start complaining. In this case, explain that their site was already migrated to a new URL. Provide them with this new URL.
• Start shutting down your virtual machines that were responsible for hosting SQL and SharePoint. Make sure these VMs didn't co-host any other services. Even though it's a bad practice, many companies still do it for various reasons.
• Backup virtual machines. This is optional because it is assumed you already took SQL backups.
• Delete virtual machines completely.
• 1-5 years later: remove all your backups (SQL and/or VMs) if they are not needed any longer.