I couldn\'t find any mention of local datastore location config param in current Appengine java documentation.
I remember some years ago there was this key: -D
It's not mentioned in the documentation but it still works.
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.target.version}</version>
<configuration>
<jvmFlags>
<jvmFlag>-Ddatastore.backing_store=c:/temp/ds-maven.bin
</jvmFlag>
</jvmFlags>
</configuration>
</plugin>
If you want to modify the store location without using maven, you can specify it in the command line of the dev server like this :
dev_appserver --property=datastore.backing_store=c:/temp/ds.bin <app directory>
Be careful though, since they are not documented features, Google might decide to remove them without warning.