StorPool, fast storage for fast times

At Storage Field Day 18 (SFD18) a couple of weeks ago, we heard from a new company, StorPool, that provides ultra fast software defined storage for MSPs and other cloud providers. You can watch the videos of their sessions here.

Didn’t know what to make of them at first, but when they started demoing their performance, we all woke up. They ran an all read and mixed read-write IO workload, that almost blew away any other proprietary/non-proprietary storage I’ve seen before.

[Updated 12Mar2019] What they were trying to achieve was to match the performance of an Windows Server 2019 Hyper V benchmark which hit 13.8 M IOPS using 12 nodes of 384GB DRAM, 1.5TB Optane DC persistent memory, 32TB (4X8TB) NVMe SSDs and Mellanox 25Gbps RDMA ethernet, with each VM running on the server that had the VHDX file stored.

Their demo showed 70:30 R:W random 4KB mixed workload and achieved 1M IOPS with a read latency of 140 microsec. and write latency of 100 microsec. (end to end at the VM level). [Updated 12Mar2019] They were able to match the performance of a published benchmark without the 1.5TB Optane memory, without the 25Gbps RDMA Ethernet and without having the VMs and its storage running on same nodes. They were able to show this performance running StorPool, KVM and CentOS 7 across 12 nodes running both VMs and storage services.

They also showed information on a pgbench benchmark, which I was not familiar with. The chart had response times on the horizontal axis and TPS performance on the vertical axis.

What’s even more amazing is that even with the great performance they still offer reasonable data services such as CoW snapshots, asynchronous replication (with changed block tracking), thin provisioning, end to end data integrity, and iSCSI support.

Their target market is mostly MSPs and large customers moving to the private cloud configurations. They mentioned deep support for OpenNebula, [updated 12Mar2019] OpenStack, OnApp and Kubernetes which means each virtual disk is a volume/LUN. They support VMware and Windows Server/Hyper-V through iSCSI.

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The fact that they have a proprietary protocol is not that great but if they can generate the IOPS and response times they showed here with snapshot, thin provisioning and asynch replication, I’m ok with it. [Updated 12Mar2019]The fact that they were able to match the performance of the more expensive system with standard Ethernet, no Optane memory and all VMs running remote made a significant impression on me.

Want to learn more, check out these other discussions on StorPool (and other SFD18 vendors):

SFD18 – as intense as it gets by Max Mortillaro (@DarkAvenger), and

Podcast #3 review the SFD18 presenters by Chris M. Evans (@ChrisMEvans) and Matt Leib (@MBLeib).

[Updated 12Mar2019 Boyan Krosnov sent me an email indicating that the post had made some mistakes in the post which were corrected via updates above. Editors ]

Faster Docker initialization through Slacker snapshots & NFS storage

Just got back from EMCWorld2016 this week but on the way there and back I was perusing the FAST’16 papers. One of the papers I read  (see Slacker: Fast Distribution with Lazy Docker Containers, p. 181) discussed performance problems with initializing Docker container micro-services and how they could be solved using persistent, intelligent NFS storage.

It appears that Docker container initialization spends a lot of time provisioning and initializing a local file system for each container.  Docker containers typically make use of an AUFS (Another Union File System) storage driver which makes use of another file system (like ext4) as its underlying storage which has beneath it either DAS or external storage.

When using persistent and intelligent NFS storage, Docker can take advantage of storage system snapshots and cloning to improve container initialization significantly. In the paper, the researchers used Tintri as the underlying persistent, enterprise class NFS storage but I believe the functionality that’s taken advantage of is available with most enterprise class NAS systems and as such, is readily available with other storage subsystems.
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Storage systems on Agile

640px-Scrum_FrameworkWas talking with Qumulo‘s CEO Peter Godman earlier this week for another GreyBeards On Storage Podcast (not available yet). One thing he said which was hard for me to comprehend was that they were putting out a new storage software release every 2 weeks.

Their customers are updating their storage system software every 2 weeks.

In my past life as a storage systems development director, we would normally have to wait months if not quarters before customers updated their systems to the latest release. As a result, we strived to put out an update at most, once a quarter with a major release every year to 18 months or so.

To me releasing code to the field every two weeks sounds impossible or at best very risky. Then I look at my iPhone. I get updates from Twitter, Facebook, LinkedIN and others, every other week. And Software-as-a-service (SaaS) solutions often update their systems frequently, if not every other week. Should storage software be any different?

It turns out Peter and his development team at Qumulo have adopted SaaS engineering methodology, which I believe uses Agile development.

Agile development

As I understand it Agile development has a couple of tenets (see Wikipedia article for more information):

  • Individuals and interaction – leading to co-located teams, with heavy use of pair programming, and developer generated automated testing, rather than dispersed teams with developers and QA separate but (occasionally) equal.
  • Working software – using working software as a means of validating requirements, showing off changes and modifying code rather than developing reams of documentation.
  • (Continuous) Customer collaboration – using direct engagement with customers over time to understand changes (using working software) rather than one time contracts for specifications of functionality
  • Responding to change – changing direction in real time using immediate customer feedback rather than waiting months or a year or more to change development direction to address customer concerns.

In addition to all the above, Agile development typically uses Scrum for product planning. An Agile Scrum (see picture above & Wikipedia article) is a weekly (maybe daily) planning meeting, held standing up and discussing what changes go into the code next.

This is all fine for application development which involves a few dozen person years of effort but storage software development typically takes multiple person centuries of development & QA effort. In my past life, our storage system regression testing typically took 24 hours or more and proper QA validation took six months or more of elapsed time with ~ 5 person years or so of effort, not to mention beta testing the system at a few, carefully selected customer sites for 6 weeks or more. How can you compress this all into a few weeks?

Software development on Agile

With Agile, you probably aren’t beta testing a new release for 6 weeks anywhere, anymore. While you may beta test a new storage system for a period of time you can’t afford the time to do this on subsequent release updates anymore.

Next, there is no QA. It’s just a developer/engineer and their partner. Together they own code change and its corresponding test suite. When one adds functionality to the system, it’s up to the team to add new tests to validate it. Test automation helps streamline the process.

Finally, there’s continuous integration to the release code in flight. Used to be a developer would package up a change, then validate it themselves (any way they wanted), then regression test it integrated with the current build, and then if it was deemed important enough, it would be incorporated into the next (daily) build of the software. If it wasn’t important, it could wait on the shelf (degenerating over time due to lack of integration) until it came up for inclusion. In contrast, I believe Agile software builds happen hourly or even more often (in real time perhaps), changes are integrated as soon as they pass automated testing, and are never put on the shelf. Larger changes may still be delayed until a critical mass is available, but if it’s properly designed even major changes can be implemented incrementally. Once in the build, automated testing insures that any new change doesn’t impact working functionality.

Due to the length of our update cycle, we often had 2 or more releases being validated at any one time. Unclear to me whether Agile allows for multiple releases in flight as it just adds to the complexity and any change may  have to be tailored for each release it goes into.

Storage on Agile

Vendors are probably not doing this with hardware that’s also undergoing significant change. Trying to do both would seem suicidal.

Hardware modifications often introduce timing alterations that can expose code bugs that had never been seen before. Hardware changes also take a longer time to instantiate (build into electronics). This can be worked around by using hardware simulators but timing is often not the same as the real hardware and it can take 10X to 100X more real-time to execute simple operations. Nonetheless, new hardware typically takes weeks to months to debug and this can be especially hard if the software is changing as well.

Similar to hardware concerns, OS or host storage protocol changes (say from NFSv3 to NFSv4) would take a lot more testing/debugging to get right.

So it helps if the hardware doesn’t change, the OS doesn’t change and the host IO protocol doesn’t change when your using Agile to develop storage software.

The other thing that we ran into is that over time, regression testing just kept growing and took longer and longer to complete. We made it a point of adding regression tests to validate any data loss fix we ever had in the field. Some of these required manual intervention (such as hardware bugs that need to be manually injected). This is less of a problem with a new storage system and limited field experience, but over time fixes accumulate and from a customer perspective, tests validating them are hard to get rid of.

Hardware on Agile

Although a lot of hardware these days is implemented as ASICs, it can also be implemented via Field Programmable Gate Arrays (FPGAs). Some FPGAs can be configured at runtime (see Wikipedia article on FPGAs), that is in the field, almost on demand.

FPGA programming is done using a hardware description language, an electronic logic coding scheme. It looks very much like software development of hardware logic. Why can’t this be incrementally implemented, continuously integrated, automatically validated and released to the field every two weeks.

As discussed above, the major concern is that new hardware introducing timing changes which expose hard to find (software and hardware) bugs.

And incremental development of original hardware, seems akin to having a building’s foundation changing while your adding more stories. One needs a critical mass of hardware to get to a base level of functionality to run storage functionality. This is less of a problem when one’s adding or modifying functionality for current running hardware.

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I suppose Qumulo’s use of Agile shouldn’t be much of a surprise. They’re a startup, with limited resources, and need to play catchup with a lot of functionality to implement. It’s risky from my perspective but you have to take calculated risks if your going to win the storage game.

You have to give Qumulo credit for developing their storage using Agile and being gutsy enough to take it directly to the field. Let’s hope it continues to work for them.

Photo Credits“Scrum Framework” by Source (WP:NFCC#4). Licensed under Fair use via Wikipedia

Peak server, the cloud & NetApp storage for AWS

I was at a conference a month or so ago and one speaker mentioned that the number of x86 servers being sold has peaked and is dropping. I can imagine a number of reasons for this and the main one being server virtualization. But this speaker had a different view and it seemed to be the cloud.

Peak server is here.

He said that three companies were purchasing over 1/2 the x86 servers these days. I feel that there should be at least four Google, Facebook, Amazon & Microsoft and maybe five, if you add in Apple.

Something has happened over the past year or so. Enterprise IT has continued along its merry way but the adoption of cloud services is starting to take off.

I have seen this before, with mainframes, then mini-computers, and now client-server. Minicomputers came out and were so easy to use and develop/deploy applications on, that people stopped creating new apps on the mainframe. Mainframes never died out, and probably have never really stopped shipping increasing MIPS every year. But the share of WW MIP installations for mainframes has been shrinking for decades and have never got going again.

Ultimately, the proprietary minicomputer was just a passing fad and only lasted about 25 years or so. It was wounded by the PC, and then killed off by proprietary Unix workstations.

Then it happened again, the new upstart this time was Windows Server and Linux. Once again it was just easier to build apps on these new and cheaper servers, than any of the older Unix servers. Of course there’s still plenty of business in proprietary Unix servers, but again I would venture to say that their share of WW installed MIPS has been shrinking for a long time.

Nowadays, the cloud is mortally wounding the server market. Server virtualization is helping a lot but it’s also enabling the cloud to eliminate many physical server sales. This is because new applications, new IT environments are being ported/moved/deployed onto the cloud.

Peak server means less enterprise networking, storage and server hardware

In this new, cloud world, customers need less servers, less networking and less enterprise class storage. Yes not every application is suitable to cloud deployment but that’s why there’s still mainframes, still Unix servers, and a continuing need for standalone, physical or virtual x86 servers in the enterprise. But their share of MIPs will start shrinking soon if it hasn’t already.

Ok, so enterprise data center share of MIPs will start shrinking vis a vis cloud data centers. But what happens to networking and storage. My view is that networking becomes software defined and there’s a component of that which operates on special purpose hardware. This will increase in shipments but the more complex, enterprise class networking equipment will flatline and never see any more substantial growth.

And up until yesterday I felt much the same about enterprise class storage. Software defined storage in my future, DAS and SSDs for the capacity and the smarts exist in software if at all. Today, most of the cloud and many service providers have been moving off enterprise class storage and onto DAS.

NetApp’s new enterprise storage in AWS

But yesterday I heard about NetApp private storage for the cloud. This is a configuration of NetApp storage installed in a CoLo facility with a “direct connection” to Amazon compute cloud. In this way, enterprise customers can maintain data stewardship/ownership/governance over their data while at the same time deploying applications onto AWS compute cloud.

This seems to be one of the sticking points to enterprise customers adopting the cloud. By having (data) storage owned lock/stock&barrel by the enterprise it seems much easier and less risky to deploy new and old applications to the cloud.

Whether this pans out and can provide enough value to cover the added expense of the enterprise class storage, only the market can decide. But this is the first time I can remember, where any vendor has articulated a role for enterprise class storage in the cloud. Let’s hope it works.

Image: PDP8/s by ajmexico

EMCworld 2013 Day 3

IMG_1431Rich Napolitano, President Unified Storage Division got up and showed some technology demonstrations of what they had working in their labs.  Rich had some of his long time engineers up on the stage to show what was running in their labs.

  • First up was a dual controller, dual processors per controller 8 core processing chips (32cores in all) running against an all SSD backend. The configuration was up for a short time but it seemed like 96 SSDs, so an all-flash VNX array.  They used Iometer, random-8KB IO to drive almost 975K IOPS at sub-msec. response time. They hit 1M IOPS with just slightly above 1 msec. response time. You could see the processor utilization of the 32 cores going up as the workload reached higher levels.  Couldn’t see precisely but all the cores were running at ~70-80% busy at the 1Miops level and it seemed like the system performance was entering the knee-of-the-curve
  • Next up was the new VNX data app store demonstration. Similar to iPhone and Android App stores. EMC has identified a select set of apps that can be run directly on VNX hardware. The current demonstration had two versions of anti-virus, Recover Point Virtual Appliance (vRPA), (v?)VPLEX, CloudAccess and MySQL server.  The engineers showed how AV software could be installed and be running on the VNX as well as how vRPA could be installed and provide onboard replication services.
  • Then, they demonstrated a VNX virtual appliance (vVNX?) which was able to run on white box server which I think was running ESX.  In this case, vVNX was running with onboard DAS storage but had all the advanced functionality of VNX
  • Finally, they showed a vVNX running in a cloud services environment. Not sure if this was VMware vCloud or some other compute cloud but Rich stated that they will support many clouds.  With vVNX running in the cloud accessing storage behind the compute engine it’s unclear what the performance would be and how one would access the storage (file or iSCSI no doubt) but it did open up new possibilities as to where one could run VNX services.

It’s readily apparent that the next iteration of VNX software seems focused on taking advantage of multi-core processing (called MCx) to boost storage system performance, providing a virtualized environment within the VNX engine to run specialized data services and supplying a new vVNX functionality which can be deployed just about anywhere you would want.

That’s all for the public sessions, spent much of the rest of the day in NDA sessions.

I had a good time at EMCworld 2013, seeing old friends again and meeting new ones and thank EMC for inviting me.  For information on previous days at EMCworld 2013 please see my Day 1 and Day 2 posts.

Data hypervisor

(c) 2012 Silverton Consulting, Inc. All rights reserved

With all this talk of software defined networking and server virtualization where does storage virtualization stand.  I blogged about some problems with storage virtualization a week or so ago in my post on Storage Utilization is broke and this post takes it to the next level.  Also I was at a financial analyst conference this week in Vail where I heard Mark Lewis of Tekrocket but formerly of EMC discuss the need for a data hypervisor to provide software defined storage.

I now believe what we really need for true storage virtualization is a renewed focus on data hypervisor functionality.  The data hypervisor would need both a control plane and a data plane in order to function properly.   Ideally the control plane would set up the interface and routing for the data plane hardware and the server and/or backend storage would be none the wiser.

DMs everywhere

I envision a scenario where a customer’s application data is packaged with a data hypervisor which runs on a commodity data switch hardware with data plane and control plane software running on it.  Sort of creating (virtual) data machines or DMs.

All enterprise and nowadays most midrange storage provide most of the functionality of a storage control plane such as defining units of storage, setting up physical to logical storage mapping, incorporating monitoring, and management of the physical storage layer, etc.  So control planes are pervasive in today’s storage but proprietary.

In addition most storage systems have data plane functionality which operates to connect a host IO request to the actual data which resides in backend storage or internal cache.  But again although data planes are everywhere in storage today they are all proprietary to a specific vendor’s storage system.

Data switch needed

But in order to utilize a data hypervisor and create a more general purpose control plane layer, we need a more generic data plane layer that operates on commodity hardware. This is different from today’s SAN storage switches or DCB switches but similar in a some ways.

The functions of the data switch/data plane layer would be to take routing instructions from the control plane layer and direct the server IO request to the proper storage unit using the data plane layer.  Somewhere in this world view, probably at the data plane level it would introduce data protection services like RAID or other erasure coding schemes, point in time copy/clone services and replication services and other advanced storage features needed by enterprise storage today.

Also it would need to provide some automated storage movement across and within tiers of physical storage and it would connect server storage interfaces at the front end to storage interfaces at the backend.  Not unlike SAN or DCB switches but with much more advanced functionality.

Ideally data switch storage interfaces could attach to dedicated JBOD, Flash arrays as well as systems using DAS  storage.  In addition, it would be nice if the data switch could talk to real storage arrays on SAN, IP/SANs or NFS&CIFS/SMB storage systems.

The other thing one would like out of a data switch is support for a universal translator that would map one protocol to another, such as iSCSI to SAS, NFS to FC, or FC to NFS and any other combination, depending on the needs of the server and the storage in the configuration.

Now if the data switch were built on top of commodity x86 hardware and software with the data switch as just a specialized application that would create the underpinnings for a true data hypervisor with a control and data plane that could be independent and use anybody’s storage.

Data hypervisor

Assuming all this were available then we would have true storage virtualization.  With these capabilities, storage could be repurposed on the fly, added to, subtracted from, and in general be a fungible commodity not unlike server processing MIPs under VMware or Hyper-V.

Application data would then needed to be packaged into a data machine which would offer all the host services required to support host data access.  The data hypervisor would handle the linkages required to interface with the control and data layers.

Applications could be configured to utilize available storage at ease and storage could grow,  shrink or move to accommodate the required workload just as easily as VMs can be deployed today.

How we get there

Aside from the VMware, Citrix, Microsoft thrusts towards virtual storage there are plenty of storage virtualization solutions that can control most backend enterprise SAN storage. However, the problem with these solutions is that in general the execute only on a specific vendors hardware and don’t necessarily talk to DAS or JBOD storage.

In addition, not all of the current generation storage virtualization solutions are unified. That is most of these today only talk FC, FCoE or iSCSI and don’t support NFS or CIFS/SMB.

These don’t appear to be insurmountable obstacles and with proper allocation of R&D funding, could all be solved.

However the more problematic is that none of these solutions operate on commodity hardware or commodity software.

The hardware is probably the easiest to deal with. Today many enterprise storage systems are built ontop of x86 processor storage controllers. Albeit sometimes they incorporate specialized packaging for redundancy and high availability.

The harder problem may be commodity software. Although the genesis for a few storage virtualization systems might come from BSD or other “commodity” software operating systems. They have been modified over the years to no longer represent anything that can run on standard off the shelf operating systems.

Then again some storage virtualization systems started out with special home grown hardware and software. As such, converting these over to something more commodity oriented would be a major transition.

But the challenge is how to get there from here and would anyone want to take this on.  The other problem is that the value add that storage vendors supply currently would be somewhat eroded.  Not unlike what happened to proprietary Unix systems with the advent of VMware.

But this will not take place overnight and the company that takes this on and makes a go at it can have a significant software monopoly that would be hard to crack.

Perhaps it will take a startup to do this but I believe the main enterprise storage vendors are best positioned to take this on.

Comments?

Genome informatics takes off at 100GB/human

All is One, the I-ching and Genome case by TheAlieness (cc) (from flickr)
All is One, the I-ching and Genome case by TheAlieness (cc) (from flickr)

Read a recent article (actually a series of charts and text) on MIT Technical Review called Bases to Bytes which discusses how the costs of having your DNA sequenced is dropping faster than Moore’s law and how storing a person’s DNA data now takes ~100GB.

Apparently Nature magazine says ~30,000 genomes have been sequenced (not counting biotech sequenced genomes), representing ~3PB of data.

Why it takes 100GB

At the moment DNA sequencing is not doing any compression, no deduplication nor any other storage efficiency tools to reduce this capacity footprint.  The 3.2Billion DNA base pairs each would take a minimum of 2 bits to store which should be ~800MB but for some reason more information about each base is saved (for future needs?) and they often re-sequence the DNA multiple times just to be sure (replica’s?).  All this seems to add up  to needing 100GB of data for a typical DNA sequencing output.

How they go from 0.8GB to 100GB with more info on each base pair and multiple copies or 125X the original data requirement is beyond me.

However, we have written about DNA informatics before (see our Dits, codons & chromozones – the storage of life post).  In that post I estimated that human DNA would need ~64GB of storage, almost right on.  (Although there was a math error somewhere in that analysis. Let’s see, 1B codons each with 64 possibilities [needing 6 bits] should require 6Bbits or ~750MB of storage, close enough).

Dedupe to the rescue

But in my view some deduplication should help.  Not clear if it’s at the Codon level or at some higher organizational level (chromosome, protein, ?)  but a “codon-differential” deduplication algorithm might just do the trick and take DNA capacity requirements down to size.  In fact with all the replication in junk DNA, it starts to looks more and more like backup sets already.

I am sure any of my Deduplication friends in the industry such as EMC Data Domain, HP StoreOnce, NetApp, SEPATON, and others would be happy to give it some thought if adequate funding were to follow.  But with this much storage at stake, some of them may take it on just to go after the storage requirements.

Gosh with a 50:1 deduplication ratio, maybe we could get a human DNA sequence down to 2GB.  Then it would only take 14EB to sequence the worlds 7B population today.

Now if we could just sequence the human microbiome with metagenomic analysis of the microbiological communities of organisms that live upon, within and around all of us.  Then we might have the answer to everything biologically we wanted to know about some person.

What we could do with all this information is another matter.

Comments?