If you're interested in using the mainframe hardware platform to save energy and take your IT infrastructure in a greener direction, here are a few best practices to keep in mind. You can find more about going green with the mainframe at the IBM System z Energy Efficiency -- Green Z web page and at Destination z, the one stop shop for everything mainframe.
1. Begin with an Enterprise goal in mind. Create lasting greenness. Small scale will yield small results. Large scale will yield bigger results. Often every project looks good and green by itself, but when added up a sub optimal data center and complex infrastructure has been created.
2. Exploit virtualization to reduce the number of servers. Reducing the number of power drawing components to a minimum directly slashes the amount of energy consumed as well as reduces the cooling requirement. LPAR technology and z/VM are proven industry leaders in security and the number of images or instances.
3. Exploit virtualization to reduce the amount of networking equipment. This includes using HiperSockets, Virtual Ethernet for Systems p and i, and OSA integrated layer 2 and 3 switching.
4. Use integrated approach to server consolidation to optimize savings. More than a single methodology needs to be applied to get the fewest number of servers. IBM’s Enterprise Computing Model for reducing thousands to 30 servers used the following approach to consolidation:
--Migrate servers delivering largest savings first (i.e., stranded infrastructure)
--Eliminate assets with lowest utilization first
--Identify assets with an upcoming compelling event to mitigate expense (upgrade, move, asset refresh)
--Aggregate by customer work portfolio to leverage strong customer buy-in
--Start with oldest technology first
--Focus on freeing up contiguous raised floor space
--Provision new applications to the mainframe or another large centralized server
5. Drive to high utilization rates. Virtualization and management of workloads is key. The Operating System must manage W/L to business priorities and dispatch in an automated manner.
6. Consolidate on large servers. Fewer larger servers will convert AC to DC more efficiently than many smaller servers with smaller and less efficient power systems. Power supplies of large servers are capable of operating at very high efficiencies (+90%).
7. Eliminate redundancy but keep high availability and Disaster Recovery capability. Have the ability to non disruptively add (and reduce) capacity for production or disaster recovery without having idle or underutilized servers. On/Off Capacity on Demand (add engines by the day) and Capacity Backup Upgrade, CBU, for Disaster Recovery increases capacity without adding server infrastructure.
8. Measure and put the costs of energy where they are incurred. Automated measuring and billing of energy makes usage part of cost and green decisions. Without energy and cooling knowledge requirements are unknown, inaccurate and often over planned leading to inefficiencies. Linkage to Total Cost of Ownership (TCO) ensures green is part of every decision. Benchmark the entire Data Center as well as local areas for continuous improvement. Use commonly accepted methodologies such as the Energy Efficiency Ratio from Green Grid Consortium.
9. Use the concept of hierarchical storage. Picking the right media and format for storing data is like picking the right vehicle for a trip. Tape, a green storage equipment star, uses the least amount of energy and should be part of the storage constellation. Disk storage should be for demanding applications that require frequent updates. The Virtual Tape Server can mask latency with many applications and is another green star in the storage constellation. Larger and slower disks use less energy and if their latency can be masked the energy efficiencies gained by their use is worth it.
10. Use the latest equipment. Newer generations of IT equipment are more energy efficient and give better performance than older IT equipment. Replace the oldest most inefficient equipment first.
For lots more about saving energy and going green with the mainframe, be sure to see the IBM System z Energy Efficiency -- Green Z web page.