Datrium this week released a software update that enables a doubling of the per-server capacity of the flash cache used with its DVX storage system for VMware virtual machines.
Datrium’s Hyperdriver 1.1 software can enable customers to boost the maximum raw capacity of the flash cache from 8 TB to 16 TB per host. Datrium storage executives claimed the “effective” flash capacity would range from 32 TB to 100 TB after data deduplication and compression.
Data reduction tends to range from 2x to 4x with databases and 5x to 10x with virtual desktop infrastructure (VDI) with the DVX system, according to Craig Nunes, vice president of marketing at Datrium. He claimed that addressing 100 TB of flash at about $100 per TB on the server would provide an “orders of magnitude difference” for users accustomed to traditional storage arrays.
The Datrium storage system consists of Distributed Execution Share Logs (DiESL) Hyperdriver software, which runs on host servers, and NetShelf disk-based appliances for durable storage on the backend. Customers supply the servers, the flash for the server-based cache and the VMware virtualization software. They manage the Datrium storage through VMware vSphere.
“People want shared storage for consolidation, but flash really ought to be in the host,” said Datrium’s CEO and founder Brian Biles, who also founded Data Domain. “If you do it right, then reads never have to leave the host to get on the SAN. It’s cheaper and faster to buy flash that way [for the server], and it’s much lower latency. Then you don’t need as much in the backend repository, so it could also be lower cost.”
Datrium DVX became generally available in January. Datrium added an “Insane Mode” feature in May that enabled users to increase the number of CPU cores applied for I/O on any given host to boost performance.
With the new DVX 1.1, customers need to get higher capacity flash drives and additional RAM to boost the per-server cache raw capacity from 8 TB to 16 TB. The DiESL Hyperdriver software continues to support 32 hosts and eight solid-state drives (SSDs) per host.
“Typically our customers don’t use more than two [SSDs], but SSDs are definitely getting bigger, so we wanted to make sure that we could facilitate migration of the bigger workload,” Biles said.
Biles said Datrium would continue to increase the maximum capacity for the flash cache over time. Datrium DVX supports any type of flash drives on the VMware compatibility list.
“We access the drives through [VMware] ESX, so it just looks like a drive to us, and then we install our file system magic on top of that,” Biles said. “Normally we recommend lower-priced drives because our software’s very friendly to spreading the load and making them last a long time. Then it’s just lower cost. But we can do whatever the customers wants to do.”
Biles said workloads that might need the extra flash cache capacity to keep all data hot include analytics with data warehouses and large file servers shared across multiple hosts.
“What happens with these powerful servers today and all the cores, each core is basically running a VM, and each VM is asking for I/O,” Nunes said. “And when all those VMs ask for all that I/O in a roughly simultaneous way, it creates that delay across the SAN. In effect, flash has gotten too fast for the SAN. Multicore servers have gotten too fast. And it’s driving the need for the relocation of flash from the array right to the server to deal with that.”