How well do you know your data and the storage platform that processes the data

Last week was consumed by many conversations on this topic. I was quite jaded, really. Unfortunately many still take a very simplistic view of all the storage technology, or should I say over-marketing of the storage technology. So much so that the end users make incredible assumptions of the benefits of a storage array or software defined storage platform or even cloud storage. And too often caveats of turning on a feature and tuning a configuration to the max are discarded or neglected. Regards for good storage and data management best practices? What’s that?

I share some of my thoughts handling conversations like these and try to set the right expectations rather than overhype a feature or a function in the data storage services.

Complex data networks and the storage services that serve it

I/O Characteristics

Applications and workloads (A&W) read and write from the data storage services platforms. These could be local DAS (direct access storage), network storage arrays in SAN and NAS, and now objects, or from cloud storage services. Regardless of structured or unstructured data, different A&Ws have different behavioural I/O patterns in accessing data from storage. Therefore storage has to be configured at best to match these patterns, so that it can perform optimally for these A&Ws. Without going into deep details, here are a few to think about:

  • Random and Sequential patterns
  • Block sizes of these A&Ws ranging from typically 4K to 1024K.
  • Causal effects of synchronous and asynchronous I/Os to and from the storage

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The burgeoning world of NVMe

When I wrote this article “Let’s smoke this storage peace pipe” 5 years ago, I quoted:

NVMe® and NVM®eF‰, as it evolves, can become the Great Peacemaker and bringing both divides and uniting them into a single storage fabric.

I envisioned NVMe® and NVMe®oF™ setting the equilibrium at the storage architecture level, finishing the great storage fabric into one. This balance in the storage ecosystem at the storage interface specifications and language-protocol level has rapidly unifying storage today, and we are already seeing the end-to-end NVMe paths directly from the PCIe bus of one host to another, via networks over Ethernet (with RoCE, iWARP, and TCP flavours) and Fibre Channel™. Technically we can have an end point device, example a tablet, talking the same NVMe language to its embedded storage as well as a cloud NVMe storage in an exascale storage far, far away. In the past, there were just too many bridges, links, viaducts, aqueducts, bypasses, tunnels, flyovers to cross just to deliver a storage command, or a data in a formats, encased and encoded (and decoded) in so many different ways.

Colours in equilibrium, like the rainbow

Simple basics of NVMe®

SATA (Serial Attached ATA) and SAS (Serial Attached SCSI) are not optimized for solid state devices. besides legacy stuff like AHCI (Advanced Host Controller Interface) in SATA, and archaic SCSI-3 primitives in SAS, NVM® has so much to offer. It can achieve very high bandwidth and support 65,535 I/O queues, each with a queue depth of 65,535. The queue depth alone is a massive jump compared to SAS which has a queue depth limit of 256.

A big part of this is how NVMe® handles I/O processing. It has a submission queue (SQ) and a completion queue (CQ), and together they are know as a Queue Pair (QP). The NVMe® controller handles tens of thousands at I/Os (reads and writes) simultaneously, alerted to switch between each SQ and CQ very quickly using the MSI or MSI-X interrupt. Think of MSI and MSI-X as a service bell, a hardware register that informs the NVM® controller when there are requests in the SQ, and informs the hosts that there are completed requests in the CQ. There will be plenty of “dings” by the MSI-X service register but the NVMe® controller can perform it very well, with some smart interrupt coalescing.

NVMe I/O processing

NVMe® 1.1, as I recalled, used to be have 3 admin commands and 10 base commands, which made it very lightweight compared to SCSI-3. However, newer commands were added to NVMe® 2.0 specifications included command sets fo key-value operations and zoned named space.

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What If – The other side of Storage FUDs

Streaming on Disney+ now is Marvel Studios’ What If…? animated TV series. In the first episode, Peggy Carter, instead of Steve Rogers, took the super soldier serum and became the first Avenger. The TV series explores alternatives and possibilities of what we may have considered as precept and the order of things.

As storage practitioners, we are often faced with certain “dogmatic” arguments which were often a mix of measured actuality and marketing magic – aka FUD (fear, uncertainty, doubt). Time and again, we are thrown a curve ball, like “Oh, your competitor can do this. Can you?” Suddenly you are feeling pinned to a corner, and the pressure to defend your turf rises. You fumbled; You have no answer; Game over!

I experienced these hearty objections many times over. The best experience was one particular meeting I had during my early days with NetApp® in 2000. I was only 1-2 months with the company, still wet between the ears with the technology. I was pitching the SnapMirror® to Ericsson Malaysia when the Scandinavian manager said, “I think you are lying!“. I was lost without a response. I fumbled spectacularly although I couldn’t remember if we won or lost that opportunity.

Here are a few I often encountered. Let’s play the game of What If …?

What If …?

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Memory cloud reality soon?

The original SAN was not always Storage Area Network. SAN had a twin nomenclature called System Area Network (SAN) back in the late 90s. Fibre Channel fabric topology (THE Storage Area Network) was only starting to take off when many of the Fibre Channel topologies at the time were either FC-AL (Fibre Channel Arbitrated Loop) or Point-to-Point. So, for a while SAN was System Area Network, or at least that was what Microsoft® wanted it to be. That SAN obviously did not take off.

System Area Network (architecture shown below) presented a high speed network where server clusters can communicate. The communication protocol of choice was VIA (Virtual Interface Adapter), and the proposed applications, notably the Microsoft® SQL Server, would use Winsock API to interface with the network services. Cache coherency in the combined memory resources of a clustered network is often the technology to ensure data synchronization, consistency and integrity.

Alas, System Area Network did not truly take off, and now it is pretty much deprecated from the Microsoft® universe.

System Area Network (SAN)

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Plotting the Crypto Coin Storage Farm

The recent craze of the Chia cryptocurrency got me excited. Mostly because it uses storage as the determinant for the Proof-of-Work consensus algorithm in a blockchain network. Yes, I am always about storage. 😉

I am not a Bitcoin miner nor am I a Chia coin farmer, and my knowledge and experience in both are very shallow. But I recently became interested in the 2 main activities of Chia – plotting and farming, because they both involved storage. I am writing this blog to find out more and document about my learning experience.

[ NB: This blog does not help you make money. It is just informational from a storage technology perspective. ]

Chia Cryptocurrency

Proof of Space and Time

Bitcoin is based on Proof-of-Work (PoW). In a nutshell, there is a complex mathematical puzzle to be solved. Bitcoin miners compete to solve this puzzle and the process uses high computational processing to solve it. Once solved, the miners are rewarded for their work.

Newer entrants like Filecoin and Chia coin (XCH) use an alternate method which is Proof-of-Space (PoS) to validate and verify the transactions. Instead of miners, Chia coin farmers have to prove to have a legitimate amount of disk and/or memory space to solve a mathematical puzzle, conceptually similar to the one in Bitcoin mining. In the beginning, this was great for folks who have unused disk space that can be “rented” out to store the crypto stuff (Note: I am not familiar with the terminology yet, and I did not want to use the word “crypto tokens” incorrectly). Storj was one of the early vendors that I remember in this space touting this method but I have not followed them for a while. Their business model might have changed.

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Is Software Defined right for Storage?

George Herbert Leigh Mallory, mountaineer extraordinaire, was once asked “Why did you want to climb Mount Everest?“, in which he replied “Because it’s there“. That retort demonstrated the indomitable human spirit and probably exemplified best the relationship between the human being’s desire to conquer the physical limits of nature. The software of humanity versus the hardware of the planet Earth.

Juxtaposing, similarities can be said between software and hardware in computer systems, in storage technology per se. In it, there are a few schools of thoughts when it comes to delivering storage services with the notable ones being the storage appliance model and the software-defined storage model.

There are arguments, of course. Some are genuinely partisan but many a times, these arguments come in the form of the flavour of the moment. I have experienced in my past companies touting the storage appliance model very strongly in the beginning, and only to be switching to a “software company” chorus years after that. That was what I meant about the “flavour of the moment”.

Software Defined Storage

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OpenZFS 2.0 exciting new future

The OpenZFS (virtual) Developer Summit ended over a weekend ago. I stayed up a bit (not much) to listen to some of the talks because it started midnight my time, and ran till 5am on the first day, and 2am on the second day. Like a giddy schoolboy, I was excited, not because I am working for iXsystems™ now, but I have been a fan and a follower of the ZFS file system for a long time.

History wise, ZFS was conceived at Sun Microsystems in 2005. I started working on ZFS reselling Nexenta in 2009 (my first venture into business with my company nextIQ) after I was professionally released by EMC early that year. I bought a Sun X4150 from one of Sun’s distributors, and started creating a lab server. I didn’t like the workings of NexentaStor (and NexentaCore) very much, and it was priced at 8TB per increment. Later, I started my second company with a partner and it was him who showed me the elegance and beauty of ZFS through the command lines. The creed of ZFS as a volume and a file system at the same time with the CLI had an effect on me. I was in love.

OpenZFS Developer Summit 2020 Logo

OpenZFS Developer Summit 2020 Logo

Exciting developments

Among the many talks shared in the OpenZFS Developer Summit 2020 , there were a few ideas and developments which were exciting to me. Here are 3 which I liked and I provide some commentary about them.

  • Block Reference Table
  • dRAID (declustered RAID)
  • Persistent L2ARC

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Kubernetes Persistent Storage Managed Well

[ Disclosure: This is a StorPool Storage sponsored blog ]

StorPool Storage – Distributed Storage

There is a rapid adoption of Kubernetes in the enterprise and in the cloud. The push for digital transformation to modernize businesses for a cloud native world in the next decade has lifted both containerized applications and the Kubernetes container orchestration platform to an unprecedented level. The application landscape, especially the enterprise, is looking at Kubernetes to address these key areas:

  • Scale
  • High performance
  • Availability and Resiliency
  • Security and Compliance
  • Controllable Costs
  • Simplified

The Persistent Storage Question

Enterprise applications such as relational databases, email servers, and even the cloud native ones like NoSQL, analytics engines, demand a single data source of truth. Fundamentals properties such as ACID (atomicity, consistency, isolation, durability) and BASE (Basic Availability, Soft State, Eventual Consistency) have to have persistent storage as the foundational repository for the data. And thus, persistent storage have rallied under Container Storage Interface (CSI), and fast becoming a de facto standard for Kubernetes. At last count, there are more than 80 CSI drivers from 60+ storage and cloud vendors, each providing block-level storage to Kubernetes pods.

However, at this juncture, Kubernetes is still very engineering-centric. Persistent storage is equally as challenging, despite all the new developments and hype around it.

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Intel is still a formidable force

It is easy to kick someone who is down. Bad news have stronger ripple effects than the good ones. Intel® is going through a rough patch, and perhaps the worst one so far. They delayed their 7nm manufacturing process, one which could have given Intel® the breathing room in the CPU war with rival AMD. And this delay has been pushed back to 2021, possibly 2022.

Intel Apple Collaboration and Partnership started in 2005

Their association with Apple® is coming to an end after 15 years, and more security flaws surfaced after the Spectre and Meltdown debacle. Extremetech probably said it best (or worst) last month:

If we look deeper (and I am sure you have), all these negative news were related to their processors. Intel® is much, much more than that.

Their Optane™ storage prowess

I have years of association with the folks at Intel® here in Malaysia dating back 20 years. And I hardly see Intel® beating it own drums when it comes to storage technologies but they are beginning to. The Optane™ revolution in storage, has been a game changer. Optane™ enables the implementation of persistent memory or storage class memory, a performance tier that sits between DRAM and the SSD. The speed and more notable the latency of Optane™ are several times faster than the Enterprise SSDs.

Intel pyramid of tiers of storage medium

If you want to know more about Optane™’s latency and speed, here is a very geeky article from Intel®:

The list of storage vendors who have embedded Intel® Optane™ into their gears is long. Vast Data, StorOne™, NetApp® MAX Data, Pure Storage® DirectMemory Modules, HPE 3PAR and Nimble Storage, Dell Technologies PowerMax, PowerScale, PowerScale and many more, cement Intel® storage prowess with Optane™.

3D Xpoint, the Phase Change Memory technology behind Optane™ was from the joint venture between Intel® and Micron®. That partnership was dissolved in 2019, but it has not diminished the momentum of next generation Optane™. Alder Stream and Barlow Pass are going to be Gen-2 SSD and Persistent Memory DC DIMM respectively. A screenshot of the Optane™ roadmap appeared in Blocks & Files last week.

Intel next generation Optane roadmap

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NetApp double stitching Data Fabric

Is NetApp® Data Fabric breaking at the seams that it chose to acquire Talon Storage a few weeks ago?

It was a surprise move and the first thing that came to my mind was “Who is Talon Storage?” I have seen that name appeared in Tech Target and CRN last year but never took the time to go in depth about their technology. I took a quick check of their FAST™ software technology with the video below:

It had the reminiscence of Andrew File System, something I worked on briefly in the 90s and WAFS (Wide Area File System), a technology buzz word in the early to mid-2000s led by Tacit Networks, a company I almost joined with a fellow NetApp-ian back then. WAFS DNA appeared ingrained in Talon Storage, after finding out that Talon’s CEO and Founder, Shirish Phatak, was the architect of Tacit Networks 20 years ago.

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