Background

I recently expanded my Veeam for Office 365 deployment to protect additional organisations but it struck me that I had no idea how much data I needed to protect from Office 365!  If this was on-premises Exchange or SharePoint data, I could have looked at the database sizes to get an idea of how much data I would likely need to protect or run some PowerShell scripts to see how much space is consumed.

So how does one check the consumed storage space for Exchange Online, SharePoint Online and OneDrive for business?

Give me the info…

First things first, get yourself logged into the Office 365 admin portal.

Now if you take a look at the side menu you will see a Reports section. Give it a click and choose ‘usage’

You will now see some usage stats for each application consumed from Office 365. Click on ‘Select a report’.

From here, let’s take a look at the Exchange Online usage stats.

If you click on Storage, you will be able to check consumed space but more importantly, you will see growth over the last 180 days. Using the growth figures, we can roughly calculate growth as a percentage. This is important for determining the space that will be required to meet your backup retention requirements.

It’s a similar story for OneDrive for business and SharePoint Online.

Using my examples above, I needed 36GB of space to protect all data at its peak consumption. After the first backup, all subsequent backup passes are incremental backups with Veeam backup for Office 365. Assuming 1% growth, then the next pass will be an additional 360MB of data and so on.

UPDATE 22/10/2018

Following a recent trip to the Veeam Vanguard summit, Veeam shared their calculation for sizing backups which is:

Thanks to Karl for capturing the formula in one of his blog posts here.

Conclusion

I hope this provides some valuable information for sizing a backup repository for your Office 365 data. It certainly helps to size for the initial pass of backup data.

Ian