The ArcGIS Data Store account is a Windows login that runs the ArcGIS Data Store service on Windows servers. The ArcGIS Data Store account also writes information to the data store backup directory, data store directory, and restore staging directory. You specify this account when you install or upgrade ArcGIS Data Store.
The ArcGIS Data Store account requires full control on the ArcGIS Data Store directory (default location is C:\arcgisdatastore), full control on the ArcGIS Data Store installation directory (default location is C:\program files\arcgis\DataStore), read and write access to the shared network backup directory, and read and write access to the restore staging directory used by the relational data store.
Prior to the 10.4 release, the ArcGIS Data Store installation set the ArcGIS Data Store account to the Windows native LocalSystem account. The LocalSystem account cannot access network locations; therefore, you were advised to change the account after installation. If you did not do this, you will need to specify a new account when you upgrade from ArcGIS 10.3.1 or 10.3 Data Store.
If you need to change the ArcGIS Data Store account after you initially create it or upgrade it, use the configureserviceaccount utility.
Local versus domain accounts
Although you have the option to use a local operating system account, Esri recommends you use a domain account for production systems. ArcGIS Data Store backups should be stored on a network shared directory so you can access them if the ArcGIS Data Store machine crashes. Only domain accounts have access to shared directories on the network.
If you choose to use a local operating system account, this account cannot access network locations and, you cannot specify a shared network location for your relational data store backups or restore staging directory.