DBA VS System Administrator

Database administrators (DBA) and System Administrators frequently get into conflict due to the overlap in the tasks they perform on a daily basis.
I have worked in many places, each have different rules. It mainly depends on the skills the individual have. If the DBA is more skillful, he or she tend to be doing more of the System admin tasks. However, when the system administrator have more technical skills, they tend to spread into the sql server/ database areas.

Here is a list of tasks that broadly fit into each role, some of them overlap.
The best environment I worked in is when the DBA and System administrators work together and trust each other and learn from each other..

I would be interested to hear your views!

System administrator

• Network
• Server hardware
• Server file/OS backup
• Offline backup
• Server upgrade and patching
• Monitoring and analysing server logs (Application/ security/ server ..etc)
• Disk space monitoring
• Third party backup tool/ Tape backup (e.g. veritas)
• Server level security (server certificates/ AD groups/ users management). Service accounts
• Server build and server rebuild (disaster recovery)
• Manager scheduled tasks
• Windows install and setup
• Windows configuration (Adding/ removing new features/ roles..etc)
• Windows cluster setup
• Allocate Lun from SAN
• Perform snapshot on volume/ server level (SAN)
• Server audits and change management
• Responsible for server security
• Manage server collation
• Server documentation
  

DBA

• Database performance monitoring
• Database server tunning (IO, memory, CPU, Network)
• Database backup and recovery
• Monitoring and analysing sql error logs/ sql agent error logs/ FT index error logs
• Database upgrade and patching
• Disk space monitoring
• Database instance security (logins and roles)/ object level permission management.
• Database / filegroup/ file restore (disaster recovery)
•  Manage SQL Server Agent scheduled tasks (create/ monitor/ troubleshoot)..
•  Database instance level configuration (e.g. setting Max server memory for an instance or configuring cpu affinity value)
• Database install and setup
• Configure database cluster
• Setup and configure High availability features (Database mirroring/ log shipping/ replication)
• Perform database snapshots
• Database audits and change management
• Responsible for Database security
• Manage database collation 
• Database documentation