C:\ Drive space on Exchange Server

Se Lai
Se Lai used Ask the Experts™
Exchange Server C:\ drive suddenly fill-up, total capacity is 900GB but now it has only 2 GB free space.

Temp= empty
Clean desk
Databases on another drive
Exchange logs on another drive
No backup logs
No extra application installed

Windows server 2016 & Exchange Server 2016

What could be the reason? Please help.

Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
I would start with TreeSize Free from jam-software.com.  It will catalog the drive and show you were all the space went.
Managing Consultant
I generally assume log files, unless otherwise indicated. Here is a script that will remove old log files:

Delete text-based Exchange log files, including those from IIS
Phillip MonkIT Manager

I use WinDirStat (+1 for providing MD5 / SHA1 hashes to verify your DL) for such emergencies.
I've had the CBS.log file balloon to enormous size before (c:\windows\logs\) on my prodcution servers, could be worth a look.
Ensure you’re charging the right price for your IT

Do you wonder if your IT business is truly profitable or if you should raise your prices? Learn how to calculate your overhead burden using our free interactive tool and use it to determine the right price for your IT services. Start calculating Now!

Se LaiSystem Administrator


Michael B. Smith

The IIS logfiles consumed 696 GB space. shell i go and run the script or remove it manually.

Michael B. SmithManaging Consultant

Whatever you prefer :-)

Either works.
William FulksSystems Analyst & Webmaster

You can go into IIS Manager and then the Logging options and specify another folder to place those logs, in case you need them. Putting them to the C: drive can cause problems like what you ran into. You can also set up an automated task to clear them whenever you need.

Here's a great little guide from Microsoft - https://docs.microsoft.com/en-us/iis/manage/provisioning-and-managing-iis/managing-iis-log-file-storage
Edward van BiljonMessaging and Collaboration Technical Lead (Exchange MVP & MCT)


There are a number of log files that don't get truncated with backups. You can find my clear logs script on the technet gallery and it should clear a couple of gigs of space

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial