Log shipping is a critical feature for disaster recovery. It allows you to automate the backing up of a database (the publisher) and restoring its transaction logs on one or more standby databases (the subscribers). The process runs automatically throughout the day at the interval you specify, which creates synchronized databases.
LiteSpeed for SQL Server provides flexible backup options for log shipping and allows you to create and modify LiteSpeed log shipping plans, monitor shipping progress and troubleshoot plan problems.
There are some pre-requisites for Log Shipping to work successfully in Litespeed:
LiteSpeed for SQL Server installed on all SQL Server instances involved in log shipping.
· Microsoft SQL Server version 2000/2005/2008/2012/2014/2016.
· Publisher and subscriber must have the same SQL Server version.
· Publisher and subscriber must have the same LiteSpeed version.
· SQL Server Agent must be running for all SQL server instances involved in log shipping.
NOTE: Backup log shipping is not supported in the Express edition of SQL Server.
All databases involved in log shipping must use a full or bulk-logged recovery model.
· A database can only have one log shipping publication (LiteSpeed or native).
· A local repository must exist on both the publisher and subscriber.
· (On publisher) SQL Server Agent Service Account must have access and read/write permissions to the shared directory to write transaction log backups to. The same permissions are required for SQL Server Service Account used to initialize and reinitialize log shipping. You only need write permissions if you do not specify a local folder for the publisher.
· (On subscriber) SQL Server Agent Service Account must have access and read permissions to the shared directory to copy transaction log backups from. The same permissions are required for SQL Server Service Account used to initialize and reinitialize log shipping.
NOTE: You need to register all SQL Server instances involved in log shipping in the LiteSpeed UI Console to retrieve log shipping data for them.
By following the steps in the New Plan Wizard, you will configure the Publisher and Subscriber machine and specify the shared folder for the backup files to be copied to. It is also possible to determine the backup frequency and alert thresholds from this wizard.
A full backup is created and restored during the setup wizard (if the option is set for Litespeed to create a new full backup), and during re-initialization of the Log Shipping plan. All Log Shipping jobs only work with Transaction Log backups. (There are three jobs. One for the backup on a Publisher, and two jobs on the Subscriber machine for copy and restore operations).
Once completed, the Publisher machine will begin making transaction log backups every 15 minutes (the default time), send them to the same shared folder as before, and the Subscriber machine will copy them over and restore them, so that it will be just 15 minutes behind the data stored within the database on the Publisher machine.
Depending on Network speeds, physical distances between the machines, and database traffic during the backup times, it is possible that sometimes the backup and restore times can change, although Log Shipping backups will catch up when database or network activity reduces.
If you notice persistent alarms where backups are not copied in time, or restores are not made at the expected time interval, it may be due to these factors, in which case it is possible to amend the backup and restore times in the Log Shipping Wizard. You can also adjust the alarm threshold settings for when Litespeed expects to see a backup, copy or restore to take place. This would reduce alarms, should that become an issue.
The default recommended backup time is 15 minutes to provide an up to date Subscriber machine, but the times can vary dependent on your own business rules/requirements for the database in question.
For a more in-depth look at configuring Log Shipping, please consult the help document: