More efficient storage tiering has played a major role in JCPenney's massive energy-efficiency program, and the retailer's senior architect said he plans to add solid-state drives (SSDs) into the mix as soon as possible to save cost and space.
Daryl Molitor said his company spent more than $100 million to improve energy efficiency, and is saving 27 million kilowatt hours per year by making changes to its storage, data center and server environments.
"We're trying to become energy star certified across the board," Molitor said this week when he told his green IT story during a panel webcast sponsored by the Wikibon IT research and advisory community.
JCPenney's storage strategy to save energy is to upgrade to larger drives and arrays, reconfigure its tiers, and add solid state and data deduplication this year.
The organization's data center has approximately 1,500 storage-area network (SAN) ports. Its SAN has about 500 TB on tier 1 storage, 450 TB on tier 2 and 25 TB on tier 3. JCPenney virtualizes around 200 TB with IBM Corp.'s SAN Volume Controller (SVC).
Molitor is in the process of replacing 73 GB drives with 146 GB on tier 1 storage, and moving from 146 GB drives to 300 GB drives on tier 2. All of his tier 3 data is on 1 TB SATA drives, and JCPenney will likely move up to 2 TB and larger SATA drives as they become available.
According the Molitor, the effects are already noticeable. He said JCPenney has decreased capacity of the most expensive tier 1 disk by approximately 12% and increased tier 3 by about 47%. Using larger drives has reduced heat and electrical requirements by 20% and floor space requirements by 34%.
Molitor hopes to have two tiers within two years. SSDs will make up most of tier 1, with a tier of SATA drives behind it. From speaking with storage vendors, he estimates the price of solid-state disks has decreased by approximately 75% over the last year. If this trend continues and SSDs continue to grow larger, he believes his goal will be attainable.
JCPenney uses storage systems from EMC Corp. and IBM, and Molitor said he is looking to do a proof of concept with solid-state disk later this year and begin using it for tier 1 data next year.
"The decline in energy consumption is astronomical with solid state," he said. "I was apprehensive about solid state last year because of price, but the price has dropped and solid-state drives have gotten larger. I'm looking at going entirely with solid state to replace high-performance disk. I'm a little skeptical that the economics will work in the next two years, but that's certainly an interesting area to go down."
Molitor has also been focused on redesigning his data center. He has implemented cold locks and a hot aisle/cold aisle design, replaced HVAC units, sealed air leaks and installed heat monitoring systems. These efforts have reduced energy consumption by 40% and increased capacity.
Another big piece of the green effort is server consolidation. "We're a big believer in virtualization," he said. JCPenney is running between 400 and 500 VMware images and averaging 18 to 20 images per ESX Server. Hopefully, Molitor said, there will be between 700 and 800 VMware images by the end of the year. In addition, JCPenney has more than 200 images on seven AIX or Solaris platform servers.
But Molitor said the current economic climate might slow his plans a bit. "From our perspective, even though energy efficiency is going to save us dollars, I think the economic climate has caused us to slow down our movement in that direction because, in some cases, it costs money to save money," he said.