HI,

  We have sql mirroring configured in our environment. Every month we are restating DR DB Servers for OS patchs/maintenance activities. During this time few databases are changing their mode to suspended. Please let us know the best practice to restart DB servers with out such issues.  As of now we are restarting db servers straight away. Do we need to pause the mirroring? We have hourly Tx backups configured.

Thanks,

Varun 

https://msdn.microsoft.com/en-us/library/bb497962.aspx?f=255&MSPPError=-2147217396 

This help you.

Hi Varun,

Generally, it is better to perform the following steps in the scenario that rebooting servers.

1. Make sure that databases are synchronized on the principal server and mirror server.

2. Pause database mirroring with the following commands.

ALTER DATABASE <database_name> SET PARTNER SUSPEND

3. Resume database mirroring by using the following Transact-SQL statement after implementing OS patchs/maintenance activities.

ALTER DATABASE <database_name> SET PARTNER RESUME

There are a similar blog and a similar thread for your reference:
Stop mirroring for server reboot
Pausing DB Mirror



Thanks,
Lydia

Before maintenance window please pause the mirroring and restart once the servers are up you can resume the mirroring. Either you can do this via commands as Lydia suggested above or from GUI.

Choose mirroring monitor, there you can see the suspend option.

HI Lydia Zhang,

  Thanks for the reply. One doubt I have is We have tx backup running on Prod server. Please let me know post exec ALTER DATABASE <database_name> SET PARTNER SUSPEND   if a tx backup gets fired..  Does mirroring comesup normally?

Please help...

Thanks,

Varun