The Return of SAN and NAS with AWS?

AWS what?

Amazon Web Services announced Outposts at re:Invent last week. It was not much of a surprise for me because when AWS had their partnership with VMware in 2016, the undercurrents were there to have AWS services come right at the doorsteps of any datacenter. In my mind, AWS has built so far out in the cloud that eventually, the only way to grow is to come back to core of IT services – The Enterprise.

Their intentions were indeed stealthy, but I have been a believer of the IT pendulum. What has swung out to the left or right would eventually come back to the centre again. History has proven that, time and time again.

SAN and NAS coming back?

A friend of mine casually spoke about AWS Outposts announcements. Does that mean SAN and NAS are coming back? I couldn’t hide my excitement hearing the return but … be still, my beating heart!

I am a storage dinosaur now. My era started in the early 90s. SAN and NAS were a big part of my career, but cloud computing has changed and shaped the landscape of on-premises shared storage. SAN and NAS are probably closeted by the younger generation of storage engineers and storage architects, who are more adept to S3 APIs and Infrastructure-as-Code. The nuts and bolts of Fibre Channel, SMB (or CIFS if one still prefers it), and NFS are of lesser prominence, and concepts such as FLOGI, PLOGI, SMB mandatory locking, NFS advisory locking and even iSCSI IQN are probably alien to many of them.

What is Amazon Outposts?

In a nutshell, AWS will be selling servers and infrastructure gear. The AWS-branded hardware, starting from a single server to large racks, will be shipped to a customer’s datacenter or any hosting location, packaged with AWS popular computing and storage services, and optionally, with VMware technology for virtualized computing resources.

Taken from https://aws.amazon.com/outposts/

In a move ala-Azure Stack, Outposts completes the round trip of the IT Pendulum. It has swung to the left; it has swung to the right; it is now back at the centre. AWS is no longer public cloud computing company. They have just become a hybrid cloud computing company. Continue reading

My first TechFieldDay

[Preamble: I have been invited by  GestaltIT as a delegate to their TechFieldDay from Oct 17-19, 2018 in the Silicon Valley USA. My expenses, travel and accommodation are paid by GestaltIT, the organizer and I was not obligated to blog or promote their technologies presented at this event. The content of this blog is of my own opinions and views]

I have attended a bunch of Storage Field Days over the years but I have never attended a Tech Field Day. This coming week, I will be attending their 17th edition, TechFieldDay 17, but my first. I have always enjoyed Storage Field Days. Everytime I joined as a delegate, there were new things to discover but almost always, serendipity happened.

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Own the Data Pipeline

[Preamble: I was a delegate of Storage Field Day 15 from Mar 7-9, 2018. My expenses, travel and accommodation were paid for by GestaltIT, the organizer and I was not obligated to blog or promote the technologies presented at this event. The content of this blog is of my own opinions and views]

I am a big proponent of Go-to-Market (GTM) solutions. Technology does not stand alone. It must be in an ecosystem, and in each industry, in each segment of each respective industry, every ecosystem is unique. And when we amalgamate data, the storage infrastructure technologies and the data management into the ecosystem, we reap the benefits in that ecosystem.

Data moves in the ecosystem, from system to system, north to south, east to west and vice versa, random, sequential, ad-hoc. Data acquires different statuses, different roles, different relevances in its lifecycle through the ecosystem. From it, we derive the flow, a workflow of data creating a data pipeline. The Data Pipeline concept has been around since the inception of data.

To illustrate my point, I created one for the Oil & Gas – Exploration & Production (EP) upstream some years ago.

 

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The engineering of Elastifile

[Preamble: I was a delegate of Storage Field Day 12. My expenses, travel and accommodation were paid for by GestaltIT, the organizer and I was not obligated to blog or promote the technologies presented in this event]

When it comes to large scale storage capacity requirements with distributed cloud and on-premise capability, object storage is all the rage. Amazon Web Services started the object-based S3 storage service more than a decade ago, and the romance with object storage started.

Today, there are hundreds of object-based storage vendors out there, touting features after features of invincibility. But after researching and reading through many design and architecture papers, I found that many object-based storage technology vendors began to sound the same.

At the back of my mind, object storage is not easy when it comes to most applications integration. Yes, there is a new breed of cloud-based applications with RESTful CRUD API operations to access object storage, but most applications still rely on file systems to access storage for capacity, performance and protection.

These CRUD and CRUD-like APIs are the common semantics of interfacing object storage platforms. But many, many real-world applications do not have the object semantics to interface with storage. They are mostly designed to interface and interact with file systems, and secretly, I believe many application developers and users want a file system interface to storage. It does not matter if the storage is on-premise or in the cloud.

Let’s not kid ourselves. We are most natural when we work with files and folders.

Implementing object storage also denies us the ability to optimally utilize Flash and solid state storage on-premise when the compute is in the cloud. Similarly, when the compute is on-premise and the flash-based object storage is in the cloud, you get a mismatch of performance and availability requirements as well. In the end, there has to be a compromise.

Another “feature” of object storage is its poor ability to handle transactional data. Most of the object storage do not allow modification of data once the object has been created. Putting a NAS front (aka a NAS gateway) does not take away the fact that it is still object-based storage at the very core of the infrastructure, regardless if it is on-premise or in the cloud.

Resiliency, latency and scalability are the greatest challenges when we want to build a true globally distributed storage or data services platform. Object storage can be resilient and it can scale, but it has to compromise performance and latency to be so. And managing object storage will not be as natural as to managing a file system with folders and files.

Enter Elastifile.

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The reverse wars – DAS vs NAS vs SAN

It has been quite an interesting 2 decades.

In the beginning (starting in the early to mid-90s), SAN (Storage Area Network) was the dominant architecture. DAS (Direct Attached Storage) was on the wane as the channel-like throughput of Fibre Channel protocol coupled by the million-device addressing of FC obliterated parallel SCSI, which was only able to handle 16 devices and throughput up to 80 (later on 160 and 320) MB/sec.

NAS, defined by CIFS/SMB and NFS protocols – was happily chugging along the 100 Mbit/sec network, and occasionally getting sucked into the arguments about why SAN was better than NAS. I was already heavily dipped into NFS, because I was pretty much a SunOS/Solaris bigot back then.

When I joined NetApp in Malaysia in 2000, that NAS-SAN wars were going on, waiting for me. NetApp (or Network Appliance as it was known then) was trying to grow beyond its dot-com roots, into the enterprise space and guys like EMC and HDS were frequently trying to put NetApp down.

It’s a toy”  was the most common jibe I got in regular engagements until EMC suddenly decided to attack Network Appliance directly with their EMC CLARiiON IP4700. EMC guys would fondly remember this as the “NetApp killer“. Continue reading

Why demote archived data access?

We are all familiar with the concept of data archiving. Passive data gets archived from production storage and are migrated to a slower and often, cheaper storage medium such tapes or SATA disks. Hence the terms nearline and offline data are created. With that, IT constantly reminds users that the archived data is infrequently accessed, and therefore, they have to accept the slower access to passive, archived data.

The business conditions have certainly changed, because the need for data to be 100% online is becoming more relevant. The new competitive nature of businesses dictates that data must be at the fingertips, because speed and agility are the new competitive advantage. Often the total amount of data, production and archived data, is into hundred of TBs, even into PetaBytes!

The industries I am familiar with – Oil & Gas, and Media & Entertainment – are facing this situation. These industries have a deluge of files, and unstructured data in its archive, and much of it dormant, inactive and sitting on old tapes of a bygone era. Yet, these files and unstructured data have the most potential to be explored, mined and analyzed to realize its value to the organization. In short, the archived data and files must be democratized!

The flip side is, when the archived files and unstructured data are coupled with a slow access interface or unreliable storage infrastructure, the value of archived data is downgraded because of the aggravated interaction between access and applications and business requirements. How would organizations value archived data more if the access path to the archived data is so damn hard???!!!

An interesting solution fell upon my lap some months ago, and putting A and B together (A + B), I believe the access path to archived data can be unbelievably of high performance, simple, transparent and most importantly, remove the BLOODY PAIN of FILE AND DATA MIGRATION!  For storage administrators and engineers familiar with data migration, especially if the size of the migration is into hundreds of TBs or even PBs, you know what I mean!

I have known this solution for some time now, because I have been avidly following its development after its founders left NetApp following their Spinnaker venture to start Avere Systems.

avere_220

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Hail Hydra!

The last of the Storage Field Day 6 on November 7th took me and the other delegates to NEC. There was an obvious, yet eerie silence among everyone about this visit. NEC? Are you kidding me?

NEC isn’t exactly THE exciting storage company in the Silicon Valley, yet I was pleasantly surprised with their HydraStorprowess. It is indeed quite a beast, with published numbers of backup throughput of 4PB/hour, and scales to 100PB of capacity. Most impressive indeed, and HydraStor deserves this blogger’s honourable architectural dissection.

HydraStor is NEC’s grid-based, scale-out storage platform with an object storage backend. The technology, powered by the DynamicStor ™ software, a distributed file system laid over the HydraStor grid architecture. At the same time, it has the DataRedux™ technology that provides the global in-line deduplication as the HydraStor ingests data for data protection, replication, archiving and WORM purposes. It is a massive data consolidation platform, storing gazillion loads of data (100PB you say?) for short-term and long-term retention and recovery.

The architecture is indeed solid, and its data availability goes beyond traditional RAID-level resiliency. HydraStor employs their proprietary erasure coding, called Distributed Resilient Data™. The resiliency knob can be configured to withstand 6 concurrent disks or nodes failure, but by default configured with a resiliency level of 3.

We can quickly deduce that DynamicStor™, DataRedux™ and Distributed Resilient Data™ are the technology pillars of HydraStor. How do they work, and how do they work together?

Let’s look a bit deeper into the HydraStor architecture.

HydraStor is made up of 2 types of nodes:

  • Accelerator Nodes
  • Storage Nodes

The Accelerator Nodes (AN) are the access nodes. They interface with the HydraStor front end, which could be CIFS, NFS or OST (Open Storage Technology). The AN nodes chunks the in-coming data and performs in-line deduplication at a very high speed. It can reach speed of 300TB/hour, which is blazingly fast!

The AN nodes also runs DynamicStor™, handling the performance heavy-lifting portion of HydraStor. The chunked data from the AN nodes are then passed on to the Storage Nodes (SN), where they are further “deduped in-line” to determined if the chunks are unique or not. It is a two-step inline deduplication process. Below is a diagram showing the ANs built above the SNs in the HydraStor grid architecture.

NEC AN & SN grid architecture

 

The HydraStor grid architecture is also a very scalable architecture, allow the dynamic scale-in and scale-out of both ANs and SNs. AN nodes and SN nodes can be added or removed into the system, auto-configuring and auto-optimizing while everything stays online. This capability further strengthens the reliability and the resiliency of the HydraStor.

NEC Hydrastor dynamic topology

Moving on to DataRedux™. DataRedux™ is HydraStor’s global in-line data deduplication technology. It performs dedupe at the sub-file level, with variable length window. This is performed at the AN nodes and the SN nodes level,chunking and creating unique hash values. All unique chunks are further compressed with a modified LZ compression algorithm, shrinking the data to its optimized footprint on the disk storage. To maintain the global in-line deduplication, the hash table is available across the HydraStor cluster.

NEC Deduplication & Compression

The unique data chunk resulting from deduplication and compression are then written to disks using the configured Distributed Resilient Data™ (DRD) algorithm, at its set resiliency level.

At the junction of DRD, with erasure coding parity, the data is broken up into multiples of fragments and assigned a parity to a grouping of fragments. If the resiliency level is set to 3 (the default), the data is broken into 12 pieces, 9 data fragments + 3 parity fragments. The 3 parity fragments corresponds to the resiliency level of 3. See diagram below of the 12 fragments spread across a group of selected disks in the storage pool of the Storage Nodes.

NEC DRD erasure coding on Storage Nodes

 

If the HydraStor experiences a failure in the disks or nodes, and has resulted in the loss of a fragment or fragments, the DRD self-healing function will auto-rebuild and auto-reconfigure the recovered fragments in another set of disks, maintaining the level of 3 parities.

The resiliency level, as mentioned earlier, can be set up to 6, boosting the HydraStor survival factor of 6 disks or nodes failure in the grid. See below of how the autonomous DRD recovery works:

NEC Autonomous Data recovery

Despite lacking the razzle dazzle of most Silicon Valley storage startups and upstarts, credit be given where credit is due. NEC HydraStor is indeed a strong show stopper.

However, in a market that is as fickle as storage, deduplication solutions such as HydraStor, EMC Data Domain, and HP StoreOnce, are being superceded by Copy Data Management technology, touted by Actifio. It was rumoured that EMC restructured their entire BURA (Backup Recovery Archive) division to DPAD (Data Protection and Availability Division) to go after the burgeoning copy data management market.

It would be good if NEC can take notice and turn their HydraStor “supertanker” towards the Copy Data Management market. That would be something special to savour.

P/S: NEC. Sorry about the title. I just couldn’t resist it 😉

APIs that stick in Storage

The competition in storage networking and data management is forever going to get fiercer. And there is always going to be the question of either having open standards APIs or proprietary APIs because storage networking and data management technologies constantly have to balance between gaining a competitive advantage with proprietary APIs  or getting greater market acceptance with open standards APIs.

The flip side, is having proprietary APIs could limit and stunt the growth of the solution but with much better integration and interoperability with complementary solutions. Open standards APIs could make the entire market a plain, vanilla one where there is little difference between technology A or B or C or X, and in the long run, could give lesser incentive for technology innovation.

I am not an API guy. I do not code or do development work on APIs, but I do like APIs (Application Programming Interface). I have my fair share of APIs which can be considered open or proprietary depending on who you talk to. My understanding is that an API might be more open if there are many ISVs, developers and industry supporters endorsing it and have a valid (and usually profit-related) agenda to make the API open.

I can share some work experience with some APIs I have either worked in the past or give my views of some present cool APIs that are related to storage networking and data management.

One of the API-related works I did was with the EMC Centera. I was working with Schlumberger to create a file-level archiving/lifecycle management solution for the GeoFrame seismic files with the EMC Centera. This was back in 2008.

EMC Centera does not present itself as a NAS box (even though I believe, IDC lumps Centera sales numbers to worldwide NAS market figures, unless I am no longer correct chronologically) but rather through ISVs and application-level integration with the EMC Centera API. Here’s a high-level look of how the EMC Centera talks to application with the API.

Note: EMC Centera can also present a NAS integration interface through NFS, CIFS, HTTP and FTP protocols, but the customer must involve (may have to purchase) the EMC Centera Universal Access software appliance. This is for applications that do not have the level of development and integration to interface with the EMC Centera API. 

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NFS-phobic in Malaysia

I taught the EMC Cloud Infrastructure and Services (CIS) class last week and naturally, a few students came from the VMware space. I asked how they were implementing their storage and everyone said Fibre Channel.

I have spoken to a lot of people about this as well in the past, whether they are using SAN or NAS storage for VMware environments. And almost 99% would say SAN, either FC-SAN or iSCSI-based SAN. Why???

When I ask these people about deploying NFS, the usual reply would be related to performance.

NFS version 3 won the file sharing protocol race during its early days where Unix variants were prevalent, but no thanks to the Balkanization of Unices in the 90s. Furthermore, NFS lost quite a bit of ground between NFSv3 in 1995 and the coming out party of NFSv4.1 just 2 years ago. The in-between years were barren and NFS become quite a bit of a joke with “Need For Speed” or “No F*king Security“. That also could be a contributing factor to the NFS-phobia we see here in Malaysia.

I have experiences with both SAN and NAS and understood the respective protocols of Fibre Channel, iSCSI, NFS and CIFS, and I felt that NFS has been given unfair treatment by people in this country. For the uninformed, NFS is the only NAS protocol supported by VMware. CIFS, the Windows file sharing protocol, is not supported, probably for performance and latency reasons. However, if you catch up with high performance computing (HPC), clustering, or MPP (Massively Parallel Processing) resources, almost always you will read about NFS being involved in delivering very high performance I/O. So, why isn’t NFS proposed with confidence in VMware environments?

I have blogged about this before. And I want to use my blog today to reassert what I believe in and hope that more consideration can be given to NFS when it comes to performance, even for virtualized environments.

NFS performance is competitive when compared to Fibre Channel and in a lot of cases, better than iSCSI. It is just that the perception of poor performance in NFS is stuck in people’s mind and it is hard to change that. However, there are multiple credible sources that stated that NFS is comparable to Fibre Channel. Let me share with you one of the source that compared NFS with other transport protocols:

From the 2 graphs of IOPS and Latency, NFS fares well against other more popular transport protocols in VMware environments. Those NFS performance numbers, are probably not RDMA driven as well. Otherwise RDMA could very well boost the NFS numbers into even higher ground.

What is this RDMA (Remote Direct Memory Access)? RDMA is already making its presence felt quietly, and being used with transports like Infiniband and 10 Gigabit Ethernet. In fact, Oracle Solaris version 11 will use RDMA as the default transmission protocol whenever there is a presence of RDMA-enable NICs in the system. The diagram below shows where RDMA fits in in the network stack.

RDMA eliminates the need for the OS to participate in the delivery of data, and directly depositing the data from the initiator’s memory to the target’s memory. This eliminates traditional networking overheads such as buffers copying and setting up network data structures for the delivery. A little comparison of RDMA with traditional networking is shown below:

I was trying to find out how prevalent NFS was in supporting the fastest supercomputers in the world from the Top500 Supercomputing sites. I did not find details of NFS being used, but what I found was the Top500 supercomputers do not employ Fibre Channel SAN at all!  Most have either proprietary interconnects with some on Infiniband and 10 Gigabit Ethernet. I would presume that NFS would figure in most of them, and I am confident that NFS can be a protocol of choice for high performance environments, and even VMware environments.

The future looks bright for NFSv4. We are beginning to see the word of “parallel NFS (pNFS)” being thrown into conversations around here, and the awareness is there. NFS version 4.2 is just around the corner as well, promising greater enhancement to the protocol.