Rackspace upgrade to save $12m with Scality object storage

Rackspace expects to make savings of $12m a year in operational expenditure (opex) costs as a result of a datacentre refresh based on Scality object storage. The move – which saw it decouple server and storage hardware – has allowed it to close an entire datacentre room and reduce server count from 5,200 to 1,200.

Rackspace Cloud Office offers software as a service (SaaS), office applications and email, and has around 85,000 customers worldwide with around 8.5 million seats. Most customers are small to medium-sized enterprises (SMEs), but there are also some customers with hundreds of thousands of seats.

Previously, services had been deployed from servers with direct-attached storage with software layered on top that handled load balancing and data protection, among other things. For Rackspace Cloud Office, the server estate totalled 5,200 servers in nine rooms in three datacentres.

The key difficulties were, according to senior technical manager for R&D Dan Shain, that processing and storage couldn’t be scaled independently, which meant a server count that was far beyond optimal and which necessitated constant replacements and additions.

“We were adding 80 servers a month just to keep up,” said Shain. “And with the storage we were replacing drives at a rate of 500 a month. Keeping up was difficult and didn’t make financial sense. We wanted to separate processing from storage.”

Shain’s team evaluated 23 potential storage products and ended up with a shortlist that included Riak, MapR, Ceph, Amazon Web Services (AWS) and Scality.

The products were put through their paces in proof-of-concept testing that highlighted hardware failure scenarios and network difficulties.

Scality’s Ring object storage software product won out. Rackspace has deployed Scality Ring version 5.14 at two datacentres on 48 HPE Apollo server nodes, with 16 more due at the end of this month and an eventual roll-out of 80 planned.

That equates to around 10PB of raw storage so far, with 2.3PB useable after overheads for data protection are taken into account. All Scality nodes have flash drives for boot tasks and object storage metadata, plus 4TB or 6TB of SATA spinning disk.

The move has allowed Rackspace Cloud Office to completely decouple compute and storage and will have reduced a server count of 5,200 to 1,200 by the project’s end. This has allowed it to cut $3.2m of expenditure by being able to close down a room at its Dallas datacentre – the target is for $12m a year in opex savings overall.

“We’ve already got rid of 2,800 servers,” said Shain. “And we had been ordering two racks a month, but we’ve ordered none for the past year.”

Scality provides object storage, which does not provide the highest performance with regard to access times compared with high-end block and file storage methods but is well suited to large volumes of unstructured data.

In place of the traditional tree-like file system of network-attached storage (NAS), object storage uses a flat structure, with files given unique identifiers.