Help with 365 capacity

[jsouter]

Morning

I'm not sure where to post this, 365 admin or SP
Scenario
461 SP/Teams sites  1600 users OD sites 18TB in use 500gb left

A previous admin who left our business and was not replaced has seemingly not done a great job of managing this area, now we are facing a struggle to regain control after users where left to do what ever they want and store what ever they want it seems.
I cannot see a way how to see what sites are growing the fastest or how to scan for file types and sizes, the MS reports are of no use to me in this situation because it just shows a total size, i need to get deeper than that to find out what is being stored.

Also as global admin i don't seem to have access to to 90% of these areas so is there a way to quickly gain access of all sites and private channels.

Just after any advice really as we have been thrown in the deep end with this on top of other admin functions we manage.
Many Thanks

[#2]

Hi @jsouter 

maybe as starting point you can use the MS report to identify the sites that are using a lot of storage.

After, you can add yourself access to those sites and use the option "Storage metrics" to have a clear view of what is consuming the storage (https://sharepointmaven.com/how-to-access-storage-metrics-reports-on-a-sharepoint-site/) . You can also check if retention policies are set up and data is beeing kept on the preservation hold site library.

[#3]

Hi
Thanks for your reply, i can see the biggest sites but that isn't helping on what can be deleted, also the reports do not show which sites or one drive accounts are growing the fastest.
Also we would like to be able to scan all data SP and OD to find out what the oldest files are is there a report that shows this?

Thanks