According to Steve Etzell, director of technical architecture for Select Comfort, the company decided to move 6 terabytes (TB) of production data and 12 TB of test and development data from EMC to HDS because it liked the price it got and was impressed with HDS's technical support. Etzell said it's nothing personal against EMC -- the Symmetrix arrays, one of which will be used for another year until it officially reaches the end of its three-year service agreement, were aging and Select Comfort looked for new storage from a variety of bidders. Etzell said the company is still using EMC's Legato backup software.
But with HDS, EMC, Data Domain and Nexsan in his disk environment, Etzell had hit a quandary. "We don't have a big IT staff," he said. "We can't be managing migration between all these machines manually."
Enter OnStor's NAS gateway. Originally, Etzell said, the gateway was purchased to replace a homegrown NAS box the IT department had put together using commodity Linux servers and 4 TB of cheap Nexsan SATA disk.
"It started getting very popular with our executives," Etzell said. "We clearly needed a better system."
Select Comfort went with a gateway from OnStor to improve that system. Eztell said he preferred it to NAS from Network Appliance Inc., which he also considered, because it was disk agnostic. "Most of the reason we were changing our storage in the first place was to be able to use more cheap, commodity disk," he said.
Along the way, however, Etzell discovered that data in any file system originally created by the gateway can be moved to any other storage, regardless of the type of disk or its manufacturer. Once that connection was made, Etzell said, he decided to put the OnStor box in front of his SAN boxes, and after his environment is fully standardized on HDS, the OnStor gateway will handle data migration of file data between the test and production HDS frames, as well as from HDS to the Nexsan SATABeast. About 120 GB of file system data already written to the EMC box will also be moved to the HDS box using OnStor as well.
"We can present up to three different arrays to OnStor and it will handle the migration between tiers, as well as mirroring for data protection," Etzell said.
For data still on the EMC arrays that can't be moved by the OnStor gateway, Etzell said he plans to back up the data to the Data Domain box and then restore it to the new array, rather than having to use a costly virtualization switch, data replication or data migration tools.
"We wanted to get a new NAS box anyway to replace our homegrown job, and we wanted the Data Domain for disk based backup," he said. "But we don't have the time or money at the moment to buy a virtualization switch in addition to both of those and the new Hitachi frames, so we're using those systems to perform data migration as well."
In the end, the majority of the migration from legacy EMC to HDS will take place using Data Domain, but OnStor will do most of the replication and mirroring of data between tiers of disk once they are both in place (except for Oracle databases, for which Etzell said the company will use Oracle's hot backup feature to move data around).
"The best thing about the OnStor is how small it is -- one rack unit," Etzell said. He added that the gateway's configuration data is kept on a flash card that he can pull out and pop into another box if there's a hardware failure. He said he would also be looking into the ability to cluster the Bobcat gateways for failover.
Room for improvementFor all its simplicity and double duty as a data migration tool, Etzell said he does have one bone to pick with the Bobcat.
"The GUI could use a little help," he said. "We're finding we get more power out of a command-line interface than the OnStor GUI, just through our own trial and error."
For some functions, including NFS and CIFS on one file share and making sure permissions and user IDs are mapped properly, Etzell said his engineers have to "do some command-line magic … which goes against part of the reason we bought it because we want to be able to put anyone in front of it and have them be able to manage it."
As for the Data Domain box, "I wish it had been cheaper," Etzell said, though he did not name the price. He also said that Data Domain performs its deduplication and compression on the back end, after a full backup is sent over the wire to avoid backup bottlenecks.
"I would rather it did that on the front end," Etzell said. "It would save us time and bandwidth."
Etzell said he had also evaluated Avamar Technologies' Axion box, which performs deduplification on the front end but went with Data Domain because it would allow the Legato backup software to see it as tape.
"Avamar would have replaced our entire backup software and backup tape environment," Etzell said. "We really, really liked their product, but we didn't want to change our whole backup setup like that."