Category Archives: Disks

ZFS Replication and Recovery with FreeNAS

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We get requests to recover data from a secondary platform all the time. RPO (recovery point objective) of 30 minutes can be challenging to small to medium sized companies, especially if there is an SLA (service level agreement) to meet.

This week, my team and I took some time to create a FreeNAS replication demo for a potential client. I thought I document the whole thing about ZFS replication, the key steps to set it up and show how recovery is done.

ZFS Snapshots

ZFS replication relies on periodic ZFS snapshots. ZFS snapshot is an inherent feature from the ZFS file system, and often used as a point-in-time copy of the existing ZFS file system tree in memory. Once a snapshot has been triggered, either manually or on schedule (periodic), the file system tree and its metadata in the memory are committed to disk to ensure an updated and consistent state of the file system at all times.

To start, a running snapshot policy on a schedule must be in place. This snapshot policy can be on a specific dataset or zvol, or even the entire zpool. Yeah, I am using quite a few ZFS terminology here – zpool, zvol, dataset. You can read more about each of the structures and more here.

Once the ZFS replication task has been setup, every snapshot occurred in the snapshot policy is automatically duplicated and copied to the target ZFS dataset. Usually, the target ZFS dataset is on a secondary FreeNAS storage server, serving as a disaster recovery platform. Sending and receiving data in the snapshots rely on SSH service.

This is the network diagram explaining the FreeNAS ZFS replication setup.

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Did Cloud Kill LTFS?

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I like LTFS (Linear Tape File System). I was hoping it would take off but it has not. And looking at its future, its significance is becoming less and less relevant. I look if Cloud has been a factor in the possible demise of LTFS in the next few years.

What is LTFS?

In a nutshell, Linear Tape File System makes LTO tapes look like a disk with a file system. It takes a tape and divides it into 2 partitions:

  • Index Partition (XML Index Schema with file names, metadata and attributes details)
  • Data Partition (where the data resides)

Diagram from https://www.snia.org/sites/default/orig/SDC2011/presentations/tuesday/DavidPease_LinearTape_File_System.pdf

It has a File System module which is implemented in supported OS of Unix/Linux, MacOS and Windows. And the mounted file system “tape partition” shows up as a drive or device.

Assassination attempts

There were many attempts to kill off tapes and so far, none has been successful.

Among the “tape-killer” technologies, I think the most prominent one is the VTL (Virtual Tape Library). There were many VTLs I encountered during my days in mid-2000s. NetApp had Alacritus and EMC had Clariion Disk Libraries. There were also IBM ProtecTIER, FalconStor VTL (which is still selling today) among others and Sepaton (read in reverse is “No Tapes’). Sepaton was acquired by Hitachi Data Systems several years back. Continue reading →

The full force of Western Digital

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[Preamble: I have been invited by GestaltIT as a delegate to their Tech Field Day for Storage Field Day 18 from Feb 27-Mar 1, 2019 in the Silicon Valley USA. My expenses, travel and accommodation were covered 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]

3 weeks after Storage Field Day 18, I was still trying to wrap my head around the 3-hour session we had with Western Digital. I was like a kid in a candy store for a while, because there were too much to chew and I couldn’t munch them all.

From “Silicon to System”

Not many storage companies in the world can claim that mantra – “From Silicon to Systems“. Western Digital is probably one of 3 companies (the other 2 being Intel and nVidia) I know of at present, which develops vertical innovation and integration, end to end, from components, to platforms and to systems.

For a long time, we have always known Western Digital to be a hard disk company. It owns HGST, SanDisk, providing the drives, the Flash and the Compact Flash for both the consumer and the enterprise markets. However, in recent years, through 2 eyebrow raising acquisitions, Western Digital was moving itself up the infrastructure stack. In 2015, it acquired Amplidata. 2 years later, it acquired Tegile Systems. At that time, I was wondering why a hard disk manufacturer was buying storage technology companies that were not its usual bread and butter business.

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StorPool – Block storage managed well

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[Preamble: I have been invited by GestaltIT as a delegate to their Tech Field Day for Storage Field Day 18 from Feb 27-Mar 1, 2019 in the Silicon Valley USA. My expenses, travel and accommodation were covered 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]

Storage technology is complex. Storage infrastructure and data management operations are not trivial, despite what the hyperscalers like Amazon Web Services and Microsoft Azure would like you to think. As the adoption of cloud infrastructure services grow, the small and medium businesses/enterprises (SMB/SME) are usually left to their own devices to manage the virtual storage infrastructure. Cloud Service Providers (CSPs) addressing the SMB/SME market are looking for easier, worry-free, software-defined storage to elevate their value to their customers.

Managed high performance block storage

Enter StorPool.

StorPool is a scale-out block storage technology, capable of delivering 1 million+ IOPS with sub-milliseconds response times. As described by fellow delegate, Ray Lucchesi in his recent blog, they were able to achieve these impressive performance numbers in their demo, without the high throughput RDMA network or the storage class memory of Intel Optane. Continue reading →

Sexy HPC storage is all the rage

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HPC is sexy

There is no denying it. HPC is sexy. HPC Storage is just as sexy.

Looking at the latest buzz from Super Computing Conference 2018 which happened in Dallas 2 weeks ago, the number of storage related vendors participating was staggering. Panasas, Weka.io, Excelero, BeeGFS, are the ones that I know because I got friends posting their highlights. Then there are the perennial vendors like IBM, Dell, HPE, NetApp, Huawei, Supermicro, and so many more. A quick check on the SC18 website showed that there were 391 exhibitors on the floor.

And this is driven by the unrelentless demand for higher and higher performance of computing, and along with it, the demands for faster and faster storage performance. Commercialization of Artificial Intelligence (AI), Deep Learning (DL) and newer applications and workloads together with the traditional HPC workloads are driving these ever increasing requirements. However, most enterprise storage platforms were not designed to meet the demands of these new generation of applications and workloads, as many have been led to believe. Why so?

I had a couple of conversations with a few well known vendors around the topic of HPC Storage. And several responses thrown back were to put Flash and NVMe to solve the high demands of HPC storage performance. In my mind, these responses were too trivial, too irresponsible. So I wanted to write this blog to share my views on HPC storage, and not just about its performance.

The HPC lines are blurring

I picked up this video (below) a few days ago. It was insideHPC Rich Brueckner interview with Dr. Goh Eng Lim, HPE CTO and renowned HPC expert about the convergence of both traditional and commercial HPC applications and workloads.

I liked the conversation in the video because it addressed the 2 different approaches. And I welcomed Dr. Goh’s invitation to the Commercial HPC community to work with the Traditional HPC vendors to help push the envelope towards Exascale SuperComputing.

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Disaggregation or hyperconvergence?

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[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 covered 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]

There is an argument about NetApp‘s HCI (hyperconverged infrastructure). It is not really a hyperconverged product at all, according to one school of thought. Maybe NetApp is just riding on the hyperconvergence marketing coat tails, and just wanted to be associated to the HCI hot streak. In the same spectrum of argument, Datrium decided to call their technology open convergence, clearly trying not to be related to hyperconvergence.

Hyperconvergence has been enjoying a period of renaissance for a few years now. Leaders like Nutanix, VMware vSAN, Cisco Hyperflex and HPE Simplivity have been dominating the scene, and touting great IT benefits and eliminating IT efficiencies. But in these technologies, performance and capacity are tightly intertwined. That means that in each of the individual hyperconverged nodes, typically starting with a trio of nodes, the processing power and the storage capacity comes together. You have to accept both resources as a node. If you want more processing power, you get the additional storage capacity that comes with that node. If you want more storage capacity, you get more processing power whether you like it or not. This means, you get underutilized resources over time, and definitely not rightsized for the job.

And here in Malaysia, we have seen vendors throw in hyperconverged infrastructure solutions for every single requirement. That was why I wrote a piece about some zealots of hyperconverged solutions 3+ years ago. When you think you have a magical hammer, every problem is a nail. 😉

In my radar, NetApp and Datrium are the only 2 vendors that offer separate nodes for compute processing and storage capacity and still fall within the hyperconverged space. This approach obviously benefits the IT planners and the IT architects, and the customers too because they get what they want for their business. However, the disaggregation of compute processing and storage leads to the argument of whether these 2 companies belong to the hyperconverged infrastructure category.

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The Network is Still the Computer

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[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 covered 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]

Sun Microsystems coined the phrase “The Network is the Computer“. It became one of the most powerful ideologies in the computing world, but over the years, many technology companies have tried to emulate and practise the mantra, but fell short.

I have never heard of Drivescale. It wasn’t in my radar until the legendary NFS guru, Brian Pawlowski joined them in April this year. Beepy, as he is known, was CTO of NetApp and later at Pure Storage, and held many technology leadership roles, including leading the development of NFSv3 and v4.

Prior to Tech Field Day 17, I was given some “homework”. Stephen Foskett, Chief Cat Herder (as he is known) of Tech Field Days and Storage Field Days, highly recommended Drivescale and asked the delegates to pick up some notes on their technology. Going through a couple of the videos, Drivescale’s message and philosophy resonated well with me. Perhaps it was their Sun Microsystems DNA? Many of the Drivescale team members were from Sun, and I was previously from Sun as well. I was drinking Sun’s Kool Aid by the bucket loads even before I graduated in 1991, and so what Drivescale preached made a lot of sense to me.Drivescale is all about Scale-Out Architecture at the webscale level, to address the massive scale of data processing. To understand deeper, we must think about “Data Locality” and “Data Mobility“. I frequently use these 2 “points of discussion” in my consulting practice in architecting and designing data center infrastructure. The gist of data locality is simple – the closer the data is to the processing, the cheaper/lightweight/efficient it gets. Moving data – the data mobility part – is expensive.

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Huawei Dorado – All about Speed

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[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]

Since Storage Field Day 15 3 weeks ago, the thoughts of the session with Huawei lingered. And one word came to describe Huawei Dorado V3, their flagship All-Flash storage platform is SPEED.

My conversation with Huawei actually started the night before our planned session at their Santa Clara facility the next day. We had a evening get-together at Bourbon Levi’s Stadium. I was with my buddy, Ammar Zolkipli, who coincidentally was in the Silicon Valley for work. Ammar is from Hitachi Vantara Japan, and has been a good friend of mine for over 17 years now.

Shortly, the Huawei team arrived to join the camaraderie. And we introduced ourselves to Chun Liu, not knowing that he is the Chief Architect at Huawei. A big part of that evening was our conversation with him. Ammar and I have immersed in the Oil & Gas EP (Exploration & Production) data management and petrotechnical applications when he was in Schlumberger and after that a reseller of NetApp. I was a Consulting Engineer with NetApp back then. So, the 2 of us started blabbering (yeah, that would be us when we get together to talk technology).

I observed that Chun was very interested to find learn about real world application use cases that would push storage performance to its limits. And I guessed that the best type of I/O characteristics would be small block, random I/O and billions of them, with near-real time latency. After that evening I did some research and could only think of a few, such as deep analytics or some applications with needs for Monte Carlo simulations. Oh, well, maybe I would share that with Chun the following day.

The moment the session started, it was already about the speed prowess of Huawei Storage. It was like the greyhounds unleashed going after the rabbit. In the lineup, the Dorado series stood out.

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Magic happening

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

The magic is happening.

Dropbox, the magical disruptor, is going IPO.

When Dropbox first entered into the market which eventually termed as BYOD (Bring your Own Device), it was a phenomenon. There was nothing else that matched its simplicity and ease-of-use. A file uploaded into the cloud was instantaneously available on the tablets and smart phones. It was on every storage vendor’s presentation slides, using Dropbox as the perennial name dropping tactic to get end users buy-in.

Dropbox was more than that, and it went on to define a whole new market segment known as Enterprise File Synchronization and Sharing (EFSS), together with everybody else such as Box, Easishare (they are here in South East Asia), and just about everybody else. And the executive team at Dropbox knew they were special too, so much so that they rejected a buyout attempt by Apple in 2011.

Today, Dropbox is beyond BYOD and EFSS. They are a full fledged collaboration platform that includes project management, project workflow, file versioning, secure file transfer, smart file synchronization and Dropbox Paper. And they offer comprehensive plans from Basic, Plus and Professional to Business and Enterprise. Their upcoming IPO, I am sure, will give them far greater capital to expand, and realize their full potential as the foremost content-based collaboration platform in the world.

Dropbox began their exodus from AWS a couple of years ago. They wanted to control their destiny and have moved more than 500PB into their own private data center for their customer data. That was half-an-exabyte, people! And two years later, they saved $75million of operating costs after they exited AWS. Today, they have more than 1 Exabyte of customer data! That is just incredible.

And Dropbox’s storage architecture started with a simple foundational design called “Magic Pocket“. Magic Pocket is a “fixed-length, immutable” block storage layer.

The block size is fixed at 4MB chunks (for parallel performance and service resumption reasons), compressed and deduped (for capacity savings reasons), encrypted (for security reasons) and replicated (for high availability reasons).

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DellEMC SC progressing well

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[Preamble: I was a delegate of Storage Field Day 14. 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 haven’t had a preview of the Compellent technology for a long time. My buddies at Impact Business Solutions were the first to introduce the Compellent technology called Data Progression to the local Malaysian market and I was invited to a preview back then. Around the same time, I also recalled another rather similar preview invitation by PTC Singapore for the 3PAR technology called Adaptive Provisioning (it is called Adaptive Optimization now).

Storage tiering was on the rise in the 2009-2010 years. Both Compellent and 3PAR were neck and neck leading the conversation and mind share of storage tiering, and IBM easyTIER and EMC FAST (Fully Automated Storage Tiering) were nowhere to be seen or heard. Vividly, the Compellent Data Progression technology was much more elegant compared to the 3PAR technology. While both intelligent storage tiering technologies were equally good, I took that the 3PAR founders were ex-Sun Microsystems folks, and Unix folks sucked at UX. In this case, Compellent’s Data Progression was a definitely a leg up better than 3PAR.

History aside, this week I have the chance to get a new preview of the Compellent technology again. Compellent was now rebranded as the SC series and was positioned as the mid-range storage arrays of DellEMC. And together with the other Storage Field Day 14 delegates, I have the pleasure to experience the latest SC Data Progression technology update, as well their latest SC All-Flash.

In Data Progression, one interesting feature which caught my attention was the RAID Tiering. This was a dynamic auto expand and auto contract set of RAID tiers – RAID 10 and RAID 5/6 in the Fast Tier and RAID 5/6 in the Lower Tier. RAID 10, RAID 5 and RAID 6 on the same set of drives (including SSDs), and depending on the “hotness” of the data, the location of the data blocks switched between the several RAID tiers in the Fast Tier. Over a longer period, the data blocks would relocate transparently to the Capacity Tier from the Fast Tier.

The Data Progression technology is extremely efficient. The movement of the data between the RAID Tiers and between the Performance/Capacity Tiers are in pages instead of blocks, making the write penalty and bandwidth to a negligible minimum.

The Storage Field Day 14 delegates were also privileged to be the first to get into the deep dive of the new All-Flash SC, just days of the announcement of the All-Flash SC. The All Flash SC redefines and refines the Data Progression to the next level. Among the new optimization, NAND Flash in the SC (both SLCs and MLCs, read-intensive and write-intensive) set the Data Progression default page size from 2MB to 512KB. These smaller 512KB pages enabled reduced bandwidth for tiering between the write-intensive and the read-intensive tier.

I didn’t get the latest SC family photos yet, but I managed to grab a screenshot of the announcement from The Register of the new DellEMC SC Series.

I was very encouraged with the DellEMC Midrange Storage presentation. Besides giving us a fantastic deep dive about the DellEMC SC All-Flash Storage, I was also very impressed by the candid and straightforward attitude of the team, led by their VP of Product Management, Pierluca Chiodelli. An EMC veteran, he was taking up the hard questions onslaught by the SFD14 delegate like a pro. His team’s demeanour was critical in instilling confidence and trust in how the bloggers and the analysts viewed Dell EMC merger, and how the SC and the Unity series would pan out in the technology roadmap.

Unlike the fiasco I went through with the DellEMC Forum 2017 in Malaysia, where I was disturbed with 3 calls in 3 consecutive days by DellEMC Malaysia, I was left with a profound respect for this DellEMC Storage team. They strongly supported their position within the DellEMC storage universe, and imparted their confidence in their technology solution in the marketplace.

Without a doubt, in my point of view, this DellEMC Mid-Range Storage team was the best I have enjoyed in Storage Field Day 14. Thank you.