Can I install the BARS data source server and back up server on the same machine such as publisher? So I can use the BARS to back up the data on publisher server without installing the BARS backup server role on the other server.
You sure can :)
About Backup Targets and Data Source Servers
A backup target contains the data to be backed up for Cisco CallManager, CAR, CRS, or CER. You designate a server as a backup target during BARS installation if this server contains data to be backed up and is not the backup server. Backup targets must be configured as data source servers during BARS configuration.
You can identify the Sub as a backup target but its not a must unless you have different files in the TFTP folder that are not in the Publisher database. The Backup Target designation is usually for CRA,CER Servers etc. So 9 times out of 10 just the Publisher is configured as both the Data source and Backup server!
**For subscriber databases that are configured for backup, BARS backs up only TFTP files and CDR/CMR files.**
The following list shows the data that is backed up and restored for the Cisco CallManager publisher database:
Hosts and LMhosts files
Latest Cisco CallManager publisher database
DC Directory LDAP directory
For Cisco CallManager 3.3.x DirectoryConfiguration.ini from C:\dcdsrvr.
For Cisco CallManager 4.0(x) or later UMDirectoryConfiguration.ini.
Directory schema files avvid_schemaV*.txt
Publisher and subscriber configuration information to replication.ini file.
Cisco CallManager version to version.ini file.
If the option to backup CDR is chosen, CDR database and CDR/CMR flat files from Local CDR Path
TFTP files from C:\Program Files\Cisco\TFTPPath (the default path)
TFTP files from alternate file locations
Cisco Bulk Administration Tool (BAT) files-templates from C:\CiscoWebs\BAT, CSV files from C:\BAT and the BATversion.asp file.
HKLM\Software\Cisco Systems, Inc. (registry keys)
Cisco CallManager DSN
Security files (certificates) from under C:\Program Files\Cisco\Certificates. This applies only to Cisco CallManager 4.x or later.
LDAPConfig.ini for IPMA configuration.
From this good doc;
Hope this helps!