Manpower cuts waste with datacentre revamp

International recruitment services firm Manpower runs six datacentres across the world, serving staff in 4,000 offices in 82 countries. Two of Manpower’s datacentres are collocated, two hosted as managed services and the other two designed as disaster recovery sites.

“IT is not part of Manpower’s core business but it is a competitive strength that everyone wants to exploit to the fullest, and the expertise we get from a service provider is key to that,” says Manpower infrastructure development manager Si Chan.

Manpower switched one of its datacentre infrastructure providers and took the opportunity to revamp its storage architecture – consolidation from other datacentres and the growing mass of information created by its various divisions were outstripping available usable capacity (estimated at 20TB), and just adding more disk was expensive.

“It was not so much a cost per GB, but total spend on storage because we were using more disk,” says Chan. “Also, with faster 15,000rpm disks and solid state storage, we would be reluctant to pay the premium for hardware unless we were certain it would be fully utilised across the datacentre.”

Manpower made the decision to improve its storage utilisation and try to cut back on power consumption. Installing Compellent Storage Centre technology consolidated five EMC and IBM storage arrays down from five racks to half a rack, and used thin provisioning to create virtual storage pools that minimise capacity wastage.

The company has already revamped its datacentre network, removing up to 40 underused switches and using structured cabling to consume less power.

“We got rid of switch ports that spend their time just talking to other switch ports, put in structured cabling and put more line cards into a single chassis, saving a lot on hardware maintenance,” says Chan.

The company is now looking at how to save more power by installing new, more energy-efficient server technology. Its datacentres run a mix of Intel/AMD x86 servers and IBM pSeries/iSeries mainframe computers, running about 800 virtual machines on VMware vSphere, with a mix of Windows Server, Red Hat Enterprise Linux, IBM AIX operating systems, supporting Oracle, SQL Server and Exchange databases.

“The confusion is that the server consumes almost as much power as before, but generates more CPU power so you can use fewer servers,” says Chan. “We have economic pressures both internally and externally but we plan to take advantage of these technologies alongside virtualisation in the future.”

One unwelcome part of the move out of Manpower’s old datacentre in Warwick into a BT facility in London was the loss of the previously unmetered power supply, which meant the company could use all the electricity it wanted without restriction.

“We do not know how we had an unmetered power deal with them, but at one point they were phoning us every week to tell us we were using more power than all their other customers combined, and were putting a severe load on their resources,” says Chan. “There don’t seem to be any more unmetered power deals on the market, so the new provider [BT] has a contract limit on the average amount of power per rack.”