Enable or disable circular logging and why and when you should do this By Mariette Knap Circularloggingenabled, Get MailboxDatabase, Dismount Database, Mount Database If you are migrating from SBS 2008 with Exchange Server 2007 to Exchange Server 2013 or you are migrating from SBS 2011 with Exchange Server 2010 to Exchange Server 2016 the actual migration of the Mailboxes from the old server to the new server cause a tremendous amount of log files created if circular logging is disabled on the new server. This can cause drives to fill up and Exchange to stop working completely and if the database and log files are located on a System drive that can even lead to a non-bootable situation. It is best practice to always move the Database and Log files to a separate partition or drive as explained in How to move Exchange Server 2016 or 2013 mailbox database and logs to another drive. Enabling circular logging on the new server can improve performance a bit during your migration so let us have a look at how we change that setting. If you have enough free space you can also keep circular logging disabled but you will need an Exchange-aware backup program that can flush logs after a backup has been made. A very good read on Exchange and backup is here Everything You Need to Know About Exchange Backups* – Part 1 – You Had Me At EHLO… 1. Change circular logging from Exchange Administrative Center (EAC) From the Start menu start Exchange Administrative Center (EAC). Login with your credentials Go to Servers, Database and click the Pencil Choose Maintenance and check ‘Enable circular logging’. Click Save. Click OK Choose ‘Dismount’. Click Yes. Status of the Database shows Dismounted. Choose to Mount the Database again. Click Yes. Check the setting now and it should have been set to enabled = Checked. Click Cancel to close this window. 2. Change circular logging from Exchange Management Shell (EMS) We can do the same procedure with Powershell from within the Exchange Management Shell. Type Get-MailboxDatabase | Fl Circularloggingenabled to see what the status is of Circularlogging. It is disabled and want to enable it again. Get-MailboxDatabase | Fl Circularloggingenabled With Get-MailboxDatabase | Set-MailboxDatabase -CircularLoggingEnabled $true we enable Circular logging. With this command we enable Circular logging for ALL databases on this server. Get-MailboxDatabase | Set-MailboxDatabase -CircularLoggingEnabled $true With Get-MailboxDatabase | Dismount-Database we unmount the Database and we use Get-MailboxDatabase | Mount-Database to mount all databases on this server. Get-MailboxDatabase | Dismount-Database Get-MailboxDatabase | Mount-Database Once more we run Get-MailboxDatabase | Fl Circularloggingenabled to see what the status is. Get-MailboxDatabase | Fl Circularloggingenabled