Symptoms
Assume that you update your installation of Microsoft SQL Server Analysis Services (SSAS) 2016 to Microsoft SSAS 2017. When you synchronize a database in SSAS 2017, the synchronization takes a long time (about two hours) to finish. The same operation in SSAS 2016 takes only about 10 minutes to finish.
Resolution
This fix is included in the following update for SQL Server:
Cumulative Update 10 for SQL Server 2017
About SQL Server builds
Each new build for SQL Server contains all hotfixes and security fixes that were in the previous build. We recommend that you install the latest build for your version of SQL Server:
Workaround
To work around this problem, set the EnableDisklessTMImageSave property to 0 in the Msmdsrv.ini file (in the /OLAP/Config folder) for both the source and target servers.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the standard terminology Microsoft uses to describe software updates.