Roughly 6-7 years ago (around 2012), flash storage became affordable as a performance tier. At least, for the companies I was visiting. It was the typical “flash tier” story: buy 1-2% of flash capacity to speed everything up. All-flash storage systems were still far away into the future for them. They existed, and they were incredibly fast, but they also drove the €/GB price too far up, out of their reach.
However, in the background you could already hear the drums: it is going to be an all-flash future! Not just for performance, but also for capacity/archive storage. In fact, one of those people beating that drum was my colleague Rob. I recall vividly our “not yet!”-discussions…
And it makes sense. Solid-state drives are:
- More reliable: there are no moving parts in SSDs, and media failures are easier to correct with software/design.
- Power consumption is very low at rest: there is no little motor to keep platters spinning 24/7.
- Faster: the number of heads and the rotational speed of the platters limit a hard drive’s performance. Not so with flash!
They are still quite expensive, looking at €/TB. Fortunately, cost is coming down too. The last year or two, all flash arrays have taken flight in general-purpose workloads. Personally, I have not installed a traditional tiered SAN storage system in over a year anymore. Hyper-converged infrastructure: same story, all flash. The development of newer, cheaper types of QLC flash only helps close the gap in €/GB between HDD and SSD. But there is still a 20x gap. And one company we met at Storage Field Day 18 has a pretty solid plan to bridge that gap: VAST Data.
Our company recently replaced a lot of VNX storage by new Dell EMC Unity all-flash arrays. Since we are/were primarily a VMware hypervisor house, we decided to go ahead and create the new LUNs as VMware VMFS (Block) LUNs/datastores. This however resulted hitting us a weird and unexpected replication limit at 64 sessions.
Last week I’ve attended Dell Technologies World 2018 in Las Vegas. I was invited by Dell Technologies via the influencer program, which basically means we get access to the same content as the press or analysts. I’ve spent the weeks alternating between general keynotes, briefings, interviews and catching up with friends and colleagues. In this post I’ll try and summarize some of the main topics of the Dell Technologies World 2018, focusing on what appealed most to me.
Troubleshooting any system requires information about the configuration of the system and how it’s behaving over time. Unsurprisingly, this is also valid when you’re troubleshooting performance on a Dell EMC VNX. So help your storage engineer, and enable performance data logging on the VNX!