MS SQL Server 2017 for Linux - Installing to non default paths
You can set environment variables to control this: https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-configure-environment-variables.  When you run the mssql-conf utility (https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-configure-mssql-conf) it will pick up these values and configure them for you.

This will allow you to change your directories:


Default data directory
Default log directory
Default dump directory (memory dumps etc)
Default backup directory


and more.