The Dell EMC High-End Systems Division talked about two systems. First about the VMAX All Flash, and later about the XtremIO X2. This post is about the latter one. The XtremIO X2 builds upon the foundation of the original “old” XtremIO, but also does a couple of things differently. This post will explore those difference a bit, and will also talk about asynchronous and synchronous replication.
Excelero Storage launched their NVMesh product back in March 2017 at Storage Field Day 12. NVMesh is a software defined storage solution using commodity servers and NVMe devices. Using NVMesh and the Excelero RDDA protocol, we saw some mind blowing performance numbers, both in raw IOps and in latency, while keeping hardware and licensing costs low.
I can’t recall the last storage system installation that didn’t have some amount of solid state drives in its configuration. And for good reason: we’re rapidly getting used to the performance benefits of SSD technology. Faster applications usually result in real business value. The doctor treating patients can get his paperwork done faster and thus has time for more patients in a day. Or the batch job processing customer mailing lists or CGI renderings completes sooner, giving you a faster time to market.
To reduce the application wait times even further, solid state drives need to be able to achieve even lower latencies. Just reducing the media latency won’t cut it anymore: the software component in the chain needs to catch up. Intel is doing just that with Storage Performance Development Kit (SPDK).
NexGen has been building hybrid storages for several years: systems with spinning disks for capacity and flash for performance. This is a skill set that will not go away with the onset of all-flash Arrays. There are many types of flash available and each type of non-volatile memory will have advantages and disadvantages in capacity, performance, cost, power draw, etc. Mixing those characteristics properly inside one array allows a vendor to leverage the strengths of each technology. Say Hi to the hybrid all-flash arrays!
Not all data is accessed equally. Some data is more popular than other data that may only be accessed infrequently. With the introduction of FAST VP in the CX4 & VNX series it is possible to create a single storage pool that has multiple different types of drives. The system chops your LUNs into slices and each slice is assigned a temperature based on the activity of that slice. Heavy accessed slices are hot, infrequently accessed slices are cold. FAST VP then moves the hottest slices to the fastest tier. Once that tier is full the remaining hot slices go to the second fastest tier, etc… This does absolute wonders to your TCO: your cold data is now stored on cheap NL-SAS disks instead of expensive SSDs and your end-users won’t know a thing. There’s one scenario which will get you in trouble though and that’s infrequent, heavy use of formerly cold data…
MCx FAST Cache is an addition to the regular DRAM cache in a VNX. DRAM cache is very fast but also (relatively) expensive so an array will have a limited amount of it. Spinning disks are large in capacity and relatively cheap but slow. To bridge the performance gap there are the solid-state drives; both performance wise and cost wise somewhere between DRAM and spinning disks. There’s one problem though: a LUN usually isn’t 100% active all of the time. This means that placing a LUN on SSDs might not drive your SSDs hard enough to get the most from your investment. If only there was software that makes sure only the hottest data is placed on those SSDs and that will quickly adjust this data placement depending on the changing workload, you’d have a lot more bang for your buck. Enter MCx FAST Cache: now with an improved software stack with less overhead which results in better write performance.
When troubleshooting performance in a CLARiiON or VNX storage array you’ll often see graphs that resemble something like this: write cache maxing out to 100% on one or even two storage processors. Once this occurs the array starts a process called forced flushing to flush writes to disk and create new space in the cache for incoming writes. This absolutely wrecks the performance of all applications using the array. With the MCx cache improvements made in the VNX2 series there should be a lot less forced flushes and a much improved performance.
“Check your email ;)”. That was the first Twitter DM I read one sleepy morning in June. It’ll suffice to say, a minute later I was wide awake: I was chosen to represent the EMC Elect at the EMC “Redefine Possible” MegaLaunch event in London (UK)! I knew about these launch events because my colleague Rob attended one last year in Milan. Excitement started building and a couple of hours later I figured out I wasn’t going alone…
July 8th 2014. EMC MegaLaunch 4. Theme: Redefine Possible (or #RedefinePossible on Twitter). What previously was impossible, now is possible! Catchy theme and something that we’ve seen in IT for a number of times now. For example: In the 1990’s, who would have thought it was possible to migrate a server from one datacenter to another, possibly a couple of miles away, without downtime, in a couple of seconds?! Doing things fundamentally different, better: that’s the goal we’re always trying to achieve. So how can we apply this to Isilon?
In September 2013 EMC announced the new generation VNX with MCx technology (or VNX2). The main advantage of the new generation is a massive performance increase: with MCx technology the VNX2 can effectively use all the CPU cores available in the storage processors. Apart from a vast performance increase there’s also a boatload of new features: deduplication, active-active LUNs, smaller (256MB) chunks for FAST VP, persistent hotspares, etc. Read more about that in my previous post.
It took a while before I could get my hands on an actual VNX2 in the field. So when we needed two new VNX2 systems for a project, guess which resources I claimed to install them. Me, myself and I! Only to have a small heart attack upon unboxing the first VNX5400: someone stole my standby power supplies (SPS)!