What is the best practice for installing a XM only instance for dev locally? Should we just install XP0, and then disable xDB? There doesn't seem to be a XM single package, and when I try to install XM Scaled, it asks for a ssl cert, which we don't need for a local dev CM (I believe the XP0 doesn't need SSL for the CM).
The Sitecore Experience Management configuration (CMS-only mode) running both the Content Delivery (CD) and Content Management (CM) roles. Use this environment when you are not planning to use the Analytics and Marketing features of the Sitecore Experience Platform. When you select this topology, xDB and xConnect are not available.
After selecting your deployment topology (XP0, XM1, or XP1), you must download the corresponding web deploy packages which also contain the environment configuration files from the Sitecore Downloads page – https://dev.sitecore.net.
The following Web Deploy Packages are required for XM1 topologies:
- sitecore 9.0.0 rev. 171002 (OnPrem)_cd.scwdp.zip
- sitecore 9.0.0 rev. 171002 (OnPrem)_cm.scwdp.zip
The following environment configuration files are required for XM1 topologies:
If you want to install the XM0 topology, you only need to install the CM instance from the XM1 topology and then in the web.config file, specify the following setting:
<add key="role:define" value="Standalone" />
You don't need "Client Certificates" and "SSL Certificate for Solr".
Source: Sitecore installation Guide.
Like you said, if you just want the XM you can just install XM without XP0. The SSL cert part in the installation, it will generate for you if you don't specify the SSL cert and left it blank.