Why Dell's PS6000 isn't quite enterprise class
Still waiting for FCoE and automated tiering
Comment Dell's EqualLogic storage is positioned as enterprise storage but lacks Fibre Channel connectivity and automated data tiering.
The recently announced Dell EqualLogic PS6000 storage arrays are positioned by Dell as enterprise storage. They have iSCSI block access but, typically, major storage and system vendors position Fibre Channel-access block storage as being enterprise class with iSCSI storage targeted at applications outside corporate data centres.
With iSCSI travelling across Ethernet links and with Fibre Channel becoming available as a protocol layer on Ethernet in its Fibre Channel over Ethernet (FCoE) form then it would be relatively simple for Dell to add FCoE access to the PS6000s.
At a Dell product announcement preview event on Wednesday, Paul Sudlow, a Dell business technologist, talked about the new PS6000 range, how its 7th generation controller had twice the memory of the existing PS5000 line, a faster CPU, doubled cache, and support for Samsung 50GB solid state drives (SSD), via a separate controller, as well as SAS and SATA drives.
Performance was greatly improved. There was a 39 per cent uplift in a sequential read workload and a whopping 91 per cent uplift in a sequential write workload.
With its 4 Ethernet ports and RAID 6 protection it offered greater bandwidth and connectivity reliability and storage reliability. Existing PS storage customers can have a firmware upgrade to v4.1 get the RAID 6 feature by the way.
The product, he said, is an enterprise-class storage product but, as noted above, iSCSI is generally seen as non-enterprise data centre storage. The key to the enterprise data centre storage door is generally a Fibre Channel one.
For Fibre Channel storage applications Dell offers the OEM'ed Clariion CX4 products from EMC. Asked about FCoE for the PS6000, Sudlow said Dell was evaluating FCoE but: "We're not announcing FCoE today." Interesting.
At the same event Sudlow talked about SAN HeadQuarters (SAN HQ), the new management software for the PS6000s. It's good software that lets you monitor, manage and analyse storage activities across a group of PS storage arrays and receive alerts if problem conditions are encountered. You can check I/O throughput across a SAN, or aggregate I/O on arrays with variable timelines and variable granularity, create thinly provisioned volumes and produce various kinds of reports.
It's Dell-written software, not a product from a partner, and applicable to PS storage, not to Clariion (CX4, AX4) or Celerra (NX4) storage. Also it cannot show data tiering across different classes of storage available for the PS arrays: SATA drives, SAS ones; and SSD. In fact you can't automate this data tiering with the software.
Praveen Asthana, Dell's director of world-wide storage marketing, said it's a little early for FCoE and Dell had a few other things to do first: "Tiered data display and monitoring is a natural next stage. EqualLogic has done a lot of automated load-balancing before. The key thing is to have intelligent policies, not dumb ones. Right now we don't have policy-based tiering. We will have it."
David Graves, responsible for Dell's Analyst Relations, said: "Based on customer surveys, it doesn’t seem to be a high priority to our customer set."
With Compellent's SSD announcement you can have automatic tiering of data across SSDs and other classes of storage.This is done at the block level and I suspect that Asthana would categorise this as a relatively dumb policy with no contextual awareness of the data that the block holds.
So, let's imagine a PS6000 firmware update in the future which adds automated tiering of data based on policies, and then let's imagine what Dell might do as FCoE gets more popular and represents a requirement for enterprise data centre storage array use. An FCoE-capable PS6000 (or future PS7000) array with automated data tiering and thin provisioning would certainly fit many enterprise storage requirements and you might start asking about the need, in 2010 and 2011, for any longterm committment by Dell to physical Fibre Channel storage array connectivity. ®