Dell Inc. today added support for mixing solid-state drive (SSD) and SAS disks in the same enclosure, automated tiered storage software and greater VMware integration for its EqualLogic PS6000XVS iSCSI series, as well as 6 Gbps SAS support for its PowerVault platform.
Dell first added SSD support for EqualLogic with the introduction of the PS6000 series last year, but the PS6000XVS and PS6010XVS are the first offering from EqualLogic that allows mixing different drive types (100 GB single-level cell solid-state drives from Samsung and 450 GB SAS hard disk drives) in the same enclosure.
Dell also added an automated tiered storage feature to place data on SSD and hard disks according to access patterns, a feature that's increasingly showing up in disk array vendors looking to add SSD into their SAN products. The tiered storage feature is based on EqualLogic's automated load-balancing IP, which automatically spreads data across new disks when capacity is added. The new load balancer for tiered storage -- part of Version 5.0 of the EqualLogic firmware -- load balances by disk type rather than by RAID level within boxes with like disks. (EqualLogic has also previously supported automated tiering of larger sets of data over longer periods of time between separate arrays).
While EMC Corp. has been careful with its Fully Automated Storage Tiering (FAST) feature to leave plenty of user control and intervention features for high-end users, Dell does not allow customers to configure tiering policies or "exclude lists" for certain data. "We abstract a lot of the levers away from the user — people who have bought into EqualLogic's technology are very comfortable with array smarts putting data in the right place already," said Dell senior product manager Travis Vigil.
Liz Conner, a research analyst at IDC, said the automated tiered storage announcement from Dell isn't game-changing at this point in the market. "Coming out with more features and functionality for Dell's SMB audience is a sign the midmarket is growing more and more sophisticated," she said. "But it's nothing groundbreaking. Everyone's working on a checklist going forward that includes SSDs, virtualization, unified storage and, eventually, FCoE."
New integration with VMware and VDI
Dell's new integration with VMware vSphere's vStorage APIs are mostly focused around offloading certain processes such as snapshots and cloning to the EqualLogic disk array without using up host CPU to perform the operation or make calls to initiate it. Today such commands are launched from vCenter through the VMware host and then hit the array, which is less than optimal for performance of certain tasks. New features enabled by vStorage include SAN-accelerated provisioning to create new virtual machines (VMs), virtual machine templates, clones and linked clones; snapshot processing; and SAN-accelerated Storage VMotion.
Dell continues to cozy up to VMware customers with its iSCSI SAN features, and positions the PS6000XVS with SSDs and automated storage tiering specifically to support VMware View virtual desktop infrastructure (VDI). In particular, Vigil said, the PS6000XVS can mitigate the performance effects of the VDI "boot storm" in which large numbers of virtual desktop images must be spawned quickly when a company opens for business in the morning or resumes operations after a power outage.
Internal tests of the PS6000XVS with VMware View showed a boost in boot performance with SSDs and automated tiering, though users with sufficiently large VDI environments could theoretically run into a bottleneck between simultaneous automated tiered storage migration and the boot storm with older versions of VMware's ESX server. vSphere and vStorage now support thin clones, which preserve the changes to virtual desktop images rather than spawning new images for each new instance, which Vigil said should mitigate potential conflict between tiered storage migration and real-time demands on the storage system.
EqualLogic and VMware View customer Scott Ray, director of enterprise technology for Norwell, Mass.-based accounts receivable management firm EOS CCA, is still running ESX 3.5, but has been beta testing the PS6000XVS and Version 5.0 firmware for approximately two months. He said he simulated tests of 300 desktop users, about half of them real-world workloads and half simulated.
"We tried to simulate a load of production pool rebuild times, using the SANHQ tool readings and other monitoring tools," Ray said. The findings showed the PS6000XVS performing at 6,000 IOPS, approximately 30% to 40% better than the company's existing EqualLogic disk arrays without SSDs.
Ray said vCenter 3.5 is the limitation in his environment on the number of virtual desktops that can be spawned, rather than the EqualLogic array. "We're limited to a certain number of virtual machines with Version 3.5," he said.
MD3200 and MD3200i, new PowerVault servers and Brocade networking products
Dell also increased the capacity and performance of its low-end PowerVault MD series disk arrays for direct-attached storage (DAS) and iSCSI SAN. Up to 96 6 Gbps SAS drives are supported with the 3200 series compared with 45 3 Gbps SAS in the previous 3000 and 3000i generation of products. The 3200 is also now available in single or dual controller configurations, where previously the MD3000 supported dual controllers only. Cache supported per controller increases from 512 MB to 2 GB. Both the MD3200 and MD3200i now support up to four host ports, up from two in the previous generation. Both products now support SSD, SAS and nearline SAS drives, as opposed to SAS and SATA in the previous generation. The PowerVault MD3200 and MD3200i will be available next week and pricing starts around $11,000.
Also included with this release from Dell are new PowerVault server models and the PowerConnect J-series made by Brocade Communications Systems Inc. This is in keeping with the recent trend of end-to-end data center stack offerings, but don't look for Dell to draw lines in the sand around its infrastructure products, according to Vigil. "The problem with end-to-end stacks is that they tend to be very inflexible," he said. "We've done a lot of validation of reference designs and offer higher level management with Dell Advanced Infrastructure Manager, but our philosophy is more toward openness and flexibility."