Outlook 2016 on Office365 - Multiple huge OST file instances

[chrisjako]

i've noticed a handful of our 250+ staff have these multiple instances of OST files in their %APPDATA%\Roaming\Microsoft\Outlook folders

 

Can anyone spread some light onto what would be causing this as it's eating into my data storage

 

[synaesthesia]

Cached exchange mode... turn that off so there's no (or very little) local storage used. Means there's a pause for it to sync on startup but that's better than disk space issues.

[Boredguy]

or you can be creative and go against MS recommendations and use GPO and reg frags to point the OST to a central network location if you want to keep cached mode, but does mean users have to remember to close outlook before using it on another station.

 

Cacheless is easier

[chrisjako]

thanks for your replies - We had initially disabled cached mode but have witnessed staff waiting 5 minutes for some files to load on in subfolders before so that would introduce a new problem

[chrisjako]

but does mean users have to remember to close outlook before using it on another station.

 

Cacheless is easier

 

So yeah, this would still not happen with some of our staff even if I tattooed the instructions to the inside of their eyelids

 

What would be the consequence if/when they don't adhere to it? 2nd OST file creating, corrupt ost altogether or just not able to open outlook?

 

If its the latter option i can live with that as it'll force them to eventually learn the good practises we try to preach

[Boredguy]

It just doesn't let them load outlook on the 2nd machine.

We recommend users use the OWA where possible.

[chrisjako]

It just doesn't let them load outlook on the 2nd machine.

We recommend users use the OWA where possible.

 

Yeah we try telling them that but staff like to use the desktop version, so do I, so do not enforce it

 

Think we are going to go try the route of cached to a network store

[Boredguy]

Well network cache is not recommended, but can be setup with the following settings. We've run it for Office 2013, 2016 and our current 365 deployment

 

GPO setting is in Microsoft Outlook 201X/Miscellaneous/PST Settings

Default location for OST files \\server\share\%username%

 

GPP HKCU\Software\Microsoft\Office\1X.0\Outlook

ForceOSTPath with reg_sz value of \\server\share\%username%