OpenZFS with Object Storage

At AWS re:Invent last week, Amazon Web Services announced Amazon FSx for OpenZFS. This is the 4th managed service under the Amazon FSx umbrella, joining NetApp® ONTAP™, Lustre and Windows File Server. The highly scalable OpenZFS filesystem can provide high throughput and IOPS bandwidth to Amazon EC2, ECS, EKS and VMware® Cloud on AWS.

I am assuming the AWS OpenZFS uses EBS as the block storage backend, given the announcement that it can deliver 4GB/sec of throughput and 160,000 IOPS from the “drives” without caching. How the OpenZFS is provisioned to the AWS clients is well documented in this blog here. It is an absolutely joy (for me) to see the open source OpenZFS filesystem getting the validation and recognization from AWS. This is one hell of a filesystem.

But this blog isn’t about AWS FSx for OpenZFS with block storage. It is about what is coming, and eventually AWS FSx for OpenZFS could expand into AWS’s proficient S3 storage as well.  Can OpenZFS integrate with an S3 object storage backend? This blog looks into the burning question.

In the recently concluded OpenZFS Developer Summit 2021, one of the topics was “ZFS on Object Storage“, and the short answer is a resounding YES!

OpenZFS Developer Summit 2021

Continue reading

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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Lift and Shift Begone!

I am excited. New technologies are bringing the data (and storage) closer to processing and compute than ever before. I believe the “Lift and Shift” way would be a thing of the past … soon.

Data is heavy

Moving data across the network is painful. Moving data across distributed networks is even more painful. To compile the recent first image of a black hole, an amount of 5PB or more had to shipped for central processing. If this was moved over a 10 Gigabit network, it would have taken weeks.

Furthermore, data has dependencies. Snapshots, clones, and other data relationships with applications and processes render data inert, weighing it down like an anchor of a ship.

When I first started in the industry more than 25 years ago, Direct Attached Storage (DAS) was the dominating storage platform. I had a bulky Sun MultiDisk Pack connected via Fast SCSI to my SPARCstation 2 (diagram below):

Then I was assigned as the implementation engineer for Hock Hua Bank (now defunct) retail banking project in their Sibu HQ in East Malaysia. It was the first Sun SPARCstorage 1000 (photo below), running a direct attached Fibre Channel 0.25 Gbps FCAL (Fibre Channel Arbitrated Loop). It was the cusp of the birth of SAN (Storage Area Network).

Photo from https://www.cca.org/dave/tech/sys5/

The proliferation of SAN over the next 2 decades pushed DAS into obscurity, until SAS (Serial Attached SCSI) came about. Added to the mix was the prominence of Cloud Storage. But on-premises storage and Cloud Storage didn’t always come together. There was always a valley between the 2, until the public clouds gained a stronger foothold in the minds of IT and businesses. Today, both on-premises storage and cloud storage are slowly cosying as one Data Singularity, thanks to vision and conceptualization of data fabrics. NetApp was an early proponent of the Data Fabric concept 4 years ago. Continue reading

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

Let’s smoke the storage peace pipe

NVMe (Non-Volatile Memory Express) is upon us. And in the next 2-3 years, we will see a slew of new storage solutions and technology based on NVMe.

Just a few days ago, The Register released an article “Seventeen hopefuls fight for the NVMe Fabric array crown“, and it was timely. I, for one, cannot be more excited about the development and advancement of NVMe and the upcoming NVMeF (NVMe over Fabrics).

This is it. This is the one that will end the wars of DAS, NAS and SAN and unite the warring factions between server-based SAN (the sexy name differentiating old DAS and new DAS) and the networked storage of SAN and NAS. There will be PEACE.

Remember this?

nutanix-nosan-buntingNutanix popularized the “No SAN” movement which later led to VMware VSAN and other server-based SAN solutions, hyperconverged techs such as PernixData (acquired by Nutanix), DataCore, EMC ScaleIO and also operated in hyperscalers – the likes of Facebook and Google. The hyperconverged solutions and the server-based SAN lines blurred of storage but still, they are not the usual networked storage architectures of SAN and NAS. I blogged about this, mentioning about how the pendulum has swung back to favour DAS, or to put it more appropriately, server-based SAN. There was always a “Great Divide” between the 2 modes of storage architectures. Continue reading

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

Is there no one to challenge EMC?

It’s been a busy, busy month for me.

And when the IDC Worldwide Quarterly Disk Storage Systems Tracker for 3Q12 came out last week, I was reading in awe how impressive EMC was at the figures that came out. But most impressive of all is how the storage market continue to grow despite very challenging and uncertain business conditions. With the Eurozone crisis, China experiencing lower economic growth numbers and the uncertainty in the US economic sectors, it is unbelievable that the storage market grew 24.4% y-o-y. And for the first time, 7,104PB was shipped! Yes folks, more than 7 exabytes was shipped during that period!

In the Top 5 external disk storage market based on revenue, only EMC and HDS recorded respectable growth, recording 8.7% and 13.8% respectively. NetApp, my “little engine that could” seems to be running out of steam, earning only 0.9% growth. The rest of the field, IBM and HP, recorded negative growth. Here’s a look at the Top 5 and the rest of the pack:

HP -11% decline is shocking to me, and given the woes after woes that HP has been experiencing, HP has not seen the bottom yet. Let’s hope that the new slew of HP storage products and technologies announced at HP Discover 2012 will lift them up. It also looked like a total rebranding of the HP storage products as well, with a big play on the word “Store”. They have names like StoreOnce, StoreServ, StoreAll, StoreVirtual, StoreEasy and perhaps more coming.

The Open SAN market, which includes iSCSI has EMC again at Number 1, with 29.8%, followed by IBM (14%), HDS (12.2%) and HP (11.8%). When combined with NAS numbers, the NAS + Open SAN market, EMC has 33.5% while NetApp is 13.7%.

Of course, it is just not about external storage because the direct-attached storage numbers count too. With that, the server vendors of IBM, HP and Dell are still placed behind EMC. Here’s a look at that table from IDC:

There’s a highlight of Dell in the table above. Dell actually grew by 4.0% compared to decline in HP and IBM, gaining 0.1%. However, their numbers seem too tepid and led to the exit of Darren Thomas, Dell’s storage group head honco. News of Darren’s exit was on TheRegister.

I also want to note that NAS growth numbers actually outpaced Open SAN numbers including iSCSI.

This leads me to say that there is a dire need for NAS technical and technology expertise in the local storage market. As the adoption of NFSv4 under way and SMB 2.0 and 3.0 coming into the picture, I urge all storage networking professionals who are more pro-SAN to step out of their comfort zone and look into NAS as well. The world is changing and it is no longer SAN vs NAS anymore. And NFSv4.1 is blurring the lines even more with the concepts of layout.

But back to the subject to storage market, is there no one out there challenging EMC in a big way? NetApp was, some years ago, recorded double digit growth and challenging EMC neck-and-neck, but that mantle seems to be taken over by HDS. But both are long way to go to get close to EMC.

Kudos to the EMC team for damn good execution!

Linking Apple to SAN

Serendipity is what I would describe this encounter. I was introduced to Promise Technology Channel Sales Director early this week. When I saw his face, I realized that I already knew him, a Malaysian who previously worked at EMC in Taiwan, but has been residing in that country for many years. We laughed and joked like old buddies and hence, the story begins …

I have known of Promise through its popular VTrak storage, which many Apple users here ignorantly associate as an Apple product. Here it is, appearing on Apple’s website:

Yes, that’s the 3rd picture from your left.

Another very strong Apple product from Promise Technology is Pegasus, a storage line of direct-attached storage (DAS) sporting the Thunderbolt, a very fast interface that connects peripherals to Macs through its Mini DisplayPort. I found this strange having a graphics display port being used to connect to a storage device, but as I looked deeper into Thunderbolt, I found that the technology was meant to extend the PCIe bus with the DisplayPort into a conduit that delivers high throughput serially. Impressive!

The picture below shows the Thunderbolt link connections, in which
Intel will provide two types of Thunderbolt controllers, a 2 port type and a 1 port type.

But Thunderbolt is not a network-based technology. It is channel-based, and hence, connecting to a Fibre Channel SAN is like mixing oil with water. Apple is not known for accessing storage through Fibre Channel, and since Apple products do not have a Fibre Channel interface, Promise Technology has come up with Thunderbolt to Fibre Channel converter. They call it SANLink. And the picture below shows how it is done:

The SANLink can also be daisy-chained. In the example below, the Pegasus DAS is daisy-chained to a SANLink which then extends and expands its capacity from the Fibre Channel connected VTrak Ex30 or Ex10.

The connectivity can be 8Gbps for the VTrak Ex30, and 4Gbps for the Ex10, and it has been validated to work with MacOS X, Final Cut Studio and Apple’s Xsan.

This is targeted to the Apple’s presence in the video editing and video production environment. I have 1 customer using our storage for their Apple file sharing purpose, and I realized that these guys work in isolation most of the time. They are like a sheep-shearing house, taking one job, work on it a bit and then pass it on to another colleague for the next stage in the video production process. Sharing is clearly not well known in this type of environment. And Promise wants to change that by opening to those hermit-like video editors and producers to share and collaborate in their work.

I don’t know much about other vendors besides Apple that pushes the Thunderbolt technology. It is very high performance interface, capable of delivering 20Gbps but I am afraid that Thunderbolt may suffer from the Apple-only syndrome.

Apple tend to be very cutting-edge when it comes to most technologies that go into their products. That makes Apple high risk takers, and that puts Thunderbolt into that risky category when if Apple fails, Thunderbolt fails. So far, I have not seen Thunderbolt spreading like wildfire, but opening Apple to SAN, both iSCSI and Fibre Channel, is good. It is time Apple embrace more of the storage networking technologies and standards out there, rather than being steadfast with their proprietary implementation of storage. Apple File Protocol (AFP) and Thunderbolt (for now) comes to mind. It is good to be stubborn but …

Protogon File System

I was out shopping yesterday and I was tempted to have lunch at Bar-B-Q Plaza, a popular Thai, Japanese-style hot plate barbeque restaurant in this neck of the woods. The mascot of this restaurant is Bar-B-Gon, a dragon-like character and it is obviously a word play of barbeque and dragon.

As I was reading the news this morning about the upcoming Windows Server 8 launch, I found out that ever popular, often ridiculed NTFS (NT File System) of Windows will be going away. It will be replaced by Protogon, a codename for the new file system that Microsoft is about to release. Protogon? A word play of prototype and dragon?

The new file system, with backward compatibility with NTFS, will be called ReFS or Resilient File System. And the design objectives of what Microsoft calls “next generation” file system are clear and adept to the present day requirements. I notably mentioned present day requirements for a reason, because when I went through the key features of ReFS, the concepts and the ideas are not exactly “next generation“. Many of these features are already present with most storage vendors we know of, but perhaps for the people in the Windows world, these features might sound “next generation” to them.

ReFS, to me, is about time. NTFS has been around for a long, long time. It was first known in the wild in the 1993, and gain prominence and wide acceptance in Windows 2000 as the “enterprise-ready” file system. Indeed it was, because that was the time Microsoft Windows started its dominance into the data centers when the Unix vendors were still bickering about their version of open standards. Active Directory (AD) and NTFS were the 2 key technologies that slowly, but surely, removed Unix’s strengths in the data centers.

But over the years, as the storage networking technologies like SAN and NAS were developing and maturing, I see the NTFS being little developed to meet the strengths of these storage networking technologies and relevant protocols in the data world. When I did  a little bit of system administration on Windows (2000, 2003 notably), I could feel that NTFS was developed with direct-attached storage (DAS) or internal disks in mind. Definitely not full taking advantage of the strengths of Fibre Channel or iSCSI SAN. It was only in Windows Server 2008, that I felt Microsoft finally had enough pussyfooting with SAN and NAS, and introduced a more decent disk storage management that incorporates features that works well natively with SAN. Now, Microsoft can no longer sit quietly without acknowledging the need to build enterprise-ready technologies related to storage networking and data management. And the core in the new Microsoft Windows Server 8 engine for that is the ReFS.

One of the key technology objectives in the design of ReFS is backward compatibility. Windows has a huge market to address and they cannot just shove NTFS away. The way they did was to maintain the upper level API and file semantics and having a new core file system engine as shown in the diagram below:

ReFS is positioned with resiliency in mind. Here are a few resilient features:

  • Ability to isolate fault and perform data salvation on parts of the file system without taking the entire file system or volume offline. The goal of REFS here is to be ONLINE and serving data all the time!
  • Checksumming data and metadata for integrity. It verifies all data, and in some cases, auto-correcting corrupted data
  • Optional integrity streams that ensures protection for all forms of file-level data corruption. When enabled, whenever a file is changed, the modified copy is written to a different area of the disk than that of the original file. This way, even if the write operation is interrupted and the modified file is lost, the original file is still intact. (Doesn’t this sounds like COW with snapshots?) When combined with Storage Spaces (we will talk about this later), which can store a copy of all files in a storage array on more than one physical disk, ReFS gives Windows a way to automatically find and open an uncorrupted version of a file In the event that a file on one of the physical disks becomes corrupted. Microsoft does not recommend integrity streams for applications or systems with a specific type of storage layout or applications which want better control in the disk storage, for example databases.
  • Data scrubbing for latent disk errors. There is an tool, integrity.exe which runs and manages the data scrubbing and integrity policies. The file attribute, FILE_ATTRIBUTE_NO_SCRUB_DATA, will allow certain applications to skip this options and have these applications control integrity policies beyond what ReFS has to offer.
  • Shared storage pools across machines for additional fault tolerance and load balancing (ala Oracle RAC perhaps?)
  • Protection against bit rot. Silent data corruption, which I have blogged about many, many moons ago.

End-to-end resilient architecture is the goal in mind.

From a file structure standpoint, here’s how ReFS looks like:

ReFS is Copy-on-Write (COW). As you know, I am a big fan of any file systems but COW is one that I am most familiar with. NetApp’s Data ONTAP, Oracle Solaris, ZFS and the upcoming Linux BTRFS are all implementations of COW. Similar to BTRFS, ReFS uses a B+ tree implementation and as described in Wikipedia,

ReFS uses B+ trees for all on-disk structures including metadata and file data. The file size, total volume size, number of files in a directory and number of directories in a volume are limited by 64-bit numbers, which translates to maximum file size of 16 Exbibytes, maximum volume size of 1 Yobibyte (with 64 KB clusters), which allows large scalability with no practical limits on file and directory size (hardware restrictions still apply). Metadata and file data are organized into tables similar to relational database. Free space is counted by a hierarchal allocator which includes three separate tables for large, medium, and small chunks. File names and file paths are each limited to a 32 KB Unicode text string.

In ReFS, Microsoft introduces Storage Spaces. And the concept is very, very similar to what ZFS is, with the seamless implementation of a volume manager, RAID management, and highly resilient file system. And ZFS is 10 years old. So much for ReFS being “next generation“.  But here is a series of screenshots of how Storage Spaces looks like:

And similar to this “flexible volume management” ala ONTAP FlexVol and ZFS file systems, you can add disk drives on the fly, and grow your volumes online and real time.

ReFS inherits many of the NTFS features as it inches towards the Windows Server 8 launch date. Some of the features mentioned were the BitLocker encryption, Access Control List (ACL) for security (naturally), Symbolic Links, Volume Snapshots, File IDs and Opportunistic Locking (Oplocks).

ReFS is intended to scale to as what Microsoft says, “to extreme limits“. Here is a table describing those limits:

ReFS new technology will certainly bring Windows to the stringent availability and performance requirements of modern day file systems, but the storage networking world is also evolving into the cloud computing space. Object-based file systems are also getting involved as market trends dictate new requirements and file systems, in order to survive, must continue to evolve.

Microsoft’s file system, NTFS took a long time to come to this present version, ReFS, but can Microsoft continue to innovate to change the rules of the data storage game? We shall see …

Storage Architects no longer required

I picked up a new article this afternoon from SearchStorage – titled “Enterprise storage trends: SSDs, capacity optimization, auto tiering“. I cannot help but notice some of the things I have been writing about VMware being the storage killer and the rise of Cloud Computing which take away our jobs.

I did receive some feedback about what I wrote in the past and after reading the SearchStorage article, I can’t help but feeling justified. On the side bar, it wrote:

 

The rise of virtual machine-specific and cloud storage suggest that other changes are imminent. In both cases …. and would no longer require storage architects and managers.

Things are changing at an extremely fast pace and for those of us still languishing in the realms of NAS and SAN, our expertise could be rendered obsolete pretty quickly.

But all is not lost because it would be easier for a storage engineer, who already has the foundation to move into the virtualization space than a server virtualization engineer coming down to learn about the storage fundamentals. We can either choose to be dinosaur or be the species of the next generation.