Forum Discussion

Copper Contributor

Nov 28, 2025

Exchange database dismounted due to NTFS file extent limit reached – unexpected outage

Hi everyone, We experienced a serious outage on our Exchange 2016 server recently, and I wanted to share what we found during the root cause analysis – in case it helps someone else avoid the same s...

Copper Contributor

Dec 09, 2025

First of all, thank you for sharing your valuable insights with me. However, the issue we encountered was quite unusual. While we had no problems with other databases of similar size, the issue appeared only on a single server. For this reason, we had no choice but to migrate it onto a newly formatted disk and manually move the mailboxes.

We are currently running on Windows Server 2019. The previous setup was operating on Windows Server 2012 Standard. After the problem occurred, we performed a completely clean installation and migrated our mailboxes to the new server from scratch.

Additionally, due to certain operational requirements and architectural constraints, we are unable to run our server on any filesystem other than NTFS. Therefore, we must continue to maintain the environment on NTFS.