aa363691_leged_Installation___Nik_Patel__2
[0] My Site Host Web Application App Pool Account(e.g. sp_mysiteapp) [1] Specify this account as Web Application Pool while creating My Site Web Application from Manage Web Applications page from Central Admin Application Pool identity to run the IIS Site hosting the My Sites Web Applications and User Personal Sites as the IIS worker process. Log in to the SharePoint Server using farm account to configure My Site Host web application [3] None [4] None [5] Service Accounts in Central Admin Changes – This account is added as Web Application Pool Account for My Site Host Web Application in the Configure Service Accounts page. AD Group Membership Changes – After you create the My Site Host, machine-level permission is configured automatically Member in the WSS_WPG Member in the built-in IIS_IUSRS on IIS 7 (Windows Server 2008) and IIS 7.5 (Windows Server 2008 R2), IIS_IUSRs replaces earlier version built-in group, IIS_WPG SQL Database Changes – After you create the My Site Host, SQL Server and database permissions are configured automatically: This account is assigned to the db_owner role for the My Site Host Web application content databases. App Pool account is assigned to the WSS_CONTENT_APPLICATION_POOLS role associated with the farm configuration database. App Pool account is assigned to the WSS_CONTENT_APPLICATION_POOLS role associated with the SharePoint_Admin content database. This account will be assigned to the db_owner role for the associated user profile service application databases (e.g. Profile DB, Sync DB, and Social DB) It is important to note that this account doesn’t have access to the other service application databases like Managed Metadata or Search Service Application DBs [2] 
Must be Domain User Account. Must not be a member of the farm administrators group. Must register as SharePoint Managed Account
SharePoint 2010 Service Account References for Least-Privileged Installation | Nik Patel
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