Lessons learned from a tornado pushed Pittsburg State University to revamp its storage, replacing an older traditional...
SAN with software-defined storage.
The university in eastern Kansas implemented Hedvig storage software on Hewlett Packard Enterprise (HPE) ProLiant servers to boost replication and redundancy, said Tim Pearson, the university's assistant director of IT infrastructure and security.
Pearson said he likes that Hedvig replicates in real time to multiple sites. He uses it to replicate local snapshots between two locations on the Pittsburg campus and sends a third copy of each snapshot to Wichita State University, which is about three hours west of Pittsburg.
Pittsburg State has six HPE ProLiant servers with Hedvig software in each of the three locations for a total of 120 TB of storage capacity on the nine servers. Hedvig provides a 2-to-1 data reduction rate through inline deduplication and compression.
Hedvig formed an OEM partnership with HPE in November.
From a SAN to software-defined storage servers
A major tornado that slammed into Joplin, Mo., and surrounding areas in 2011 influenced the university's storage strategy. The Pittsburg State campus is about 45 minutes northwest of Joplin. The university relied on tape backups for its disaster recovery at that time.
With Kansas in the middle of the area known as Tornado Alley, Pearson knew his storage had to stand up if another one hit. He came to that conclusion after talking to IT colleagues in Joplin whose data centers were knocked offline for extended periods as a result of the storm, he said.
"The idea of taking our tape backups off site for recovery was something we needed to revisit," Pearson said. "We were looking for something more involved than what we had at the time."
Before the Hedvig storage, Pittsburg State relied on a two-array Dell EqualLogic iSCSI SAN. One array had 48 10,000 rpm drives; the second had 48 1 TB SATA drives. EqualLogic firmware managed data replication between the arrays. The university bought the SAN in 2011, four years after Dell acquired EqualLogic. The products are now branded as Dell EMC PS Series, although they are no longer being actively sold.
In mid-2018, Pearson said disk failures on the EqualLogic SAN reinforced the need for more resilient storage.
"Seldom a week would go by that I didn't need to replace a drive. I knew if we ever lost more than one drive, we would be unable to restore from backup," he said.
Making the Hedvig storage decision
Pearson had assembled a team of IT professionals at Pittsburg State to evaluate proposals from storage vendors, including Hedvig. The team also considered Datrium, HPE's SimpliVity, Cisco's HyperFlex hyper-converged products and a Fujitsu SAN.
"The thing we liked about Hedvig was flexibility. You could run it in a hyper-converged infrastructure environment or as storage layer on separate hardware. The support for multiple protocols would allow us to do object storage, block, NFS and Amazon S3 as we grew and our technology [needs] evolved," Pearson said.
Hedvig emerged from stealth in 2015. What concerned Pearson most was the company's relative newness. Storage customers of the startup were consulted, and Pearson said they gave Hedvig high marks about switching to a software-defined storage model.
"Every product has warts, but none of them said they regretted their decision. They all said the Hedvig support was better than they had experienced with other vendors," Pearson said.
The Hedvig storage servers use SATA disk for capacity and SSDs for performance. On the back end, NVMe flash SSDs cache and stream read data to spinning disk, as needed.
The Hedvig-HPE combination enabled Pittsburg State to reallocate the EqualLogic arrays for intraday replication, reducing the window for backup to avoid a 24-hour window. Eventually, Pearson said, Pittsburg State wants to phase out nightly snapshots and implement Hedvig scheduled snapshots.