Swap the Root Site for SharePoint Online Tenants
In August 2019, Microsoft started to roll out the SharePoint Online site swap feature. The functionality swaps out the tenant’s root site and replaces it with another site, usually a communications site. When a root site swap happens, the old root site is archived and remains available for administrative access while user traffic is directed to the site that’s swapped in.
The root site is automatically provisioned for all SharePoint Online tenants and has a URL of https://tenantname.sharepoint.com/, so it’s something like https://office365itpros.sharepoint.com/. The root site is typically the starting point for a company’s intranet, so it’s important that the site works well.
Interfaces to Swap Sites
Originally sites swaps were only possible by using the Invoke-SPOSiteSwap cmdlet. In November 2019, Microsoft updated the SharePoint Admin Center to include the Replace site option, which is only exposed when the current root site is selected (Figure 1).
Small Tenants Only
With just a few details to worry about, like choosing the right type of site to become the new root (it can’t be connected to an Office 365 group), the technology worked well. However, Microsoft restricted site swaps to Office 365 tenants with fewer than 1,000 seats. The reason for the restriction is that Microsoft wanted to be sure that everything about site swaps worked perfectly. After all, if a tenant loses access to its root site because of a bug, it will affect a lot of functionality.
Gradually Microsoft eased back the restriction to make site swap available to more tenants until they reached the 10,000 seat level and then halted. As announced in Office 365 notification MC204488 on February 22, they’re now ready to let the largest tenants go ahead and swap root sites.
Make Sure with Page Diagnostics
Large tenants often have the same kind of SharePoint activity as small tenants do; the difference is that the traffic generated by large tenant tends to expose any flaw in a process. For this reason, it’s important to do some up-front planning to make sure that the replacement root site is ready before it is swapped in.
Microsoft recommends that administrators use the Page Diagnostics tool for SharePoint Online to check replacement root sites before proceeding with a swap. This tool is an add-in for Chrome or Edge that analyzes page components to identify potential issues. For instance, if some graphics used by the page are large files, they might slow page loading. This is a bigger issue for larger sites because the higher traffic volume will accentuate the effect of the larger files.
Warnings and Errors
The page diagnostics tool reports warnings and errors. It’s up to administrators if they want to heed the warnings before proceeding (an automated checker might miss something a human knows, or humans just know best), but they can’t go ahead with a site swap if errors exist. Those errors must be fixed before a site swap is possible.
Swapping Sites in Large Tenants Needs PowerShell
When everything is ready, you can run the Invoke-SPOSiteSwap cmdlet (support in the SharePoint Admin Center for site swaps in large tenants is coming). You must update the SharePoint Online PowerShell module to version16.0.19807.1200 or higher to be able to execute a site swap in a large tenant. The easiest way to do this is by updating the module from the PowerShell Gallery:
Update-Module Microsoft.Online.Sharepoint.PowerShell -Force
The upgraded version of the cmdlet includes an integrated page diagnostic check for errors and warnings plus a new Force parameter to allow administrators to override warnings (but never errors). To perform a site swap, the command format is:
-SourceURL https://office365itpros.sharepoint.com/sites/NewMarketingComms `
-TargetURL https://office365itpros.sharepoint.com `
-ArchiveURL https://office365itpros.sharepoint.com/sites/OldMarketingComms -Force
As with anything in large organizations, it’s usual to plan operations like site swaps well ahead of time (so there’s no reason not to run page diagnostics) and to schedule the event for a period of low user activity, like a weekend. This avoid any user issues like 404 errors when the page swap is in flight.
Good SharePoint Online management is essential to the overall health of an Office 365 tenant. The Office 365 for IT Pros eBook reflects this and includes a ton of interesting and useful advice about how to work with SharePoint Online.