NetApp has announced the AFF C-Series, a new platform running ONTAP with QLC storage. Rather than a leap over the competition, this announcement seems to be about closing the gap between NetApp and Pure Storage.
The AFF C-Series is a new family of either 2U or 4U systems (with drive shelf options) that deploys with QLC flash. At launch, three models are available – the C250 (baseline 2U with 24 SSD slots, scaling to 576 drives and 35PBe), the C400 (baseline 4U, maximum 1152 drives and 71PBe), and the C800 (baseline 4U with 48 SSD slots, maximum 1728 drives and 106PBe). Remember that ONTAP systems can be deployed in HA pairs as a cluster. This allows the C-Series to reach significantly large levels of capacity, although whether customers will have the appetite (and funds) for a 106PBe system is debatable. There’s no word on pricing, but the aim is clearly to offer a more cost-competitive product to address medium performance workloads.
QLC NAND flash currently provides the highest level of density for flash drives in terms of bits per cell. As we explain in this blog post from 2018, the trade-off comes with compromises in endurance and performance. It’s worth pointing out that the endurance aspect no longer seems to be an issue for workloads that are more read-intensive than write. In any case, experience from the field shows that end users vastly overestimate the amount of write activity their systems do. This makes QLC flash suitable for many tier-1 and tier-2 workloads.
The performance aspect is more difficult to reconcile due to the processes needed to write to QLC media, including multi-step state changes. The result is lower overall latency, with NetApp suggesting around 2-4 milliseconds compared to traditional AFF with less than one millisecond and typically around 500-microsecond performance.
If some of these numbers seem familiar, then we suggest you read this post from 2019 that covers the announcement of FlashArray//C from Pure Storage. Latency figures are identical; however, NetApp offers a lower capacity entry point than FlashArray//C and higher scaling in a single HA pair. In practical terms, will customers want more than 1 petabyte of capacity in a single system? Time will tell. With any system that scales to this level, the performance capabilities become determined by the controllers, which in turn determines whether flash is the right place for the data. A lower entry point is definitely an advantage, though.
In an analyst briefing prior to the announcement of C-Series, NetApp helpfully provided comparison data to the FlashArray//C. That prompted us to check what other QLC systems are available elsewhere. Certain platforms like VAST Data have used QLC since inception but arguably targeted a different market.
If we look at solutions from Dell Technologies and HPE, we don’t see QLC in use. PowerStore still uses TLC media, while the HPE Alletra doesn’t show the specific media type at all. Only the 6000 series indicates media capacity (up to 15.36 TB), which could be QLC – we just don’t know.
IBM does use QLC flash on FlashSystem with FlashCore 2 modules. These provide up to 38.4 TB of capacity (88 TB effective) and a relatively high 2 DWPD. On a purely hardware comparison, FlashSystem might have been a better choice, but the file protocol features of ONTAP aren’t present in FlashSystem, so the functional comparison works best with FlashArray//C.
In conjunction with the C-Series launch, NetApp also announced a new entry-level A150, which is effectively a replacement for the C190 system (and enables the “C” prefix for capacity systems). More details are available here.
More interesting, though, is the additional announcement of NetApp Advance, a new set of flexible purchasing initiatives, including the Storage Lifecycle Program. Advance is all about improving the purchasing experience (which sounds very marketing) and is a theme we’ve heard elsewhere before. You can read more in this blog post from VP of Product Marketing, Jeff Baxter.
Exactly where we’ve heard about flexible purchasing models is with the revamp of Evergreen, announced by Pure Storage in June 2022. We covered the details in this blog post and accompanying podcast with Pure CTO Rob Lee.
The Architect’s View®
So, we’ve been a little cheeky by discussing the comparisons to FlashArray//C although to be fair, NetApp included the details in their briefing. In reality, a QLC AFF was definitely needed for those use cases that can’t justify the cost of using all-flash A-Series AFF. Potentially, though, the benefits go deeper. Storage optimisation has always been about tiering data onto the best solution based on cost and performance requirements. Now we must consider the environmental aspects too.
In the analyst briefing, NetApp showed an early preview of dashboard technology that will assist customers in placing data not just by cost and performance but also by sustainability factors. ONTAP can be deployed in heterogeneous clusters, which means customers can move data between hybrid, AFF A-Series and AFF C-Series to make placement decisions which could eventually calculate the emissions costs by application.
This is a much-needed catchup for NetApp, as it builds differentiation from HPE and Dell. Expect to see either a statement from HPE and/or new updates from Dell with PowerStore and QLC media – assuming the architecture can deliver it. Once again, we see the on-premises market looking to make the consumption process easier. This will continue as a theme for 2023 and 2024 as potential customers look to reduce costs and save money while demonstrating sustainability credentials.
Copyright (c) 2007-2023 – Post #65d5 – Brookend Ltd, first published on https://www.architecting.it/blog, do not reproduce without permission.