A FreeNAS Compression Tale

David vs Goliath Credit: Miguel Robledo of https://www.artstation.com/miguel_robledo

David vs Goliath

It was an underdog tale worthy of the biblical book of Samuel. When I first caught wind of how FreeNAS™ compression prowess was going against NetApp® compression and deduplication in one use case, I had to find out more. And the results in this use case was quite impressive considering that FreeNAS™ (now known as TrueNAS® CORE) is the free, open source storage operating system and NetApp® Data ONTAP, is the industry leading, enterprise, “king of the hill” storage data management software.

Certainly a David vs Goliath story.

Compression in FreeNAS

Ah, Compression! That technology that is often hidden, hardly seen and often forgotten.

Compression is a feature within FreeNAS™ that seldom gets the attention. It works, and certainly is a mature form of data footprint reduction (DFR) technology, along with data deduplication. It is switched on by default, and is the setting when creating a dataset, as shown below:

Dataset creation with Compression (lz4) turned on

The default compression algorithm is lz4 which is fast but poor in compression ratio compared to gzip and bzip2. However, lz4 uses less CPU cycles to perform its compression and decompression processing, and thus the impact on FreeNAS™ and TrueNAS® is very low.

NetApp® ONTAP, if I am not wrong, uses lzopro as default – a commercial and optimized version of the open source LZO compression library. In addition, NetApp also has their data deduplication technology as well, something OpenZFS has to improve upon in the future.

The DFR report

This brings us to the use case at one of iXsystems™ customers in Taiwan. The data to be reduced are mostly log files at the end user, and the version of FreeNAS™ is 11.2u7. There are, of course, many factors that affect the data reduction ratio, but in this case of 4 scenarios,  the end user has been running this in production for over 2 months. The results:

FreeNAS vs NetApp Data Footprint Reduction

In 2 of the 4 scenarios, FreeNAS™ performed admirably with just the default lz4 compression alone, compared to NetApp® which was running both their inline compression and deduplication.

The intention to post this report is not to show that FreeNAS™ is better in every case. It won’t be, and there are superior data footprint reduction tech out there which can outperform it. But I would expect potential and existing end users to leverage on the compression capability of FreeNAS™ which is getting better all the time.

A better compression algorithm

Followers of OpenZFS are aware of the changing of times with OpenZFS version 2.0. One exciting update is the introduction of the zstd compression algorithm into OpenZFS late last year, and is already in TrueNAS® CORE and Enterprise version 12.x.

What is zstd? zstd is a fast compression algorithm that aims to be as efficient (or better) than gzip, but with better speed closer to lz4, relatively. For a long time, the gzip compression algorithm, from levels 1-9, has been serving very good compression ratio compared to many compression algorithms, lz4 included.

However, the efficiency came at a higher processing price and thus took a longer time. At the other end, lz4 is fast and lightweight, but its reduction ratio efficiency is very poor. zstd intends to be the in-between of gzip and lz4. In the latest results published by Facebook’s github page,

zstd performance benchmark against other compression algorithms

For comparison, zstd (level -1) performed very well against zlib, the data compression library in gzip. It was made known there are 22 levels of compression in zstd but I do not know how many levels are accepted in the OpenZFS development.

At the same time, compression takes advantage of multi-core processing, and actually can speed up disk I/O response because the original dataset to be processed is smaller after the compression reduction.

While TrueNAS® still defaults lz4 compression as of now, you can probably change the default compression with a command

# zfs set compression=zstd-6 pool/dataset

Your choice

TrueNAS® and FreeNAS™ support multiple compression algorithms. lz4, gzip and now zstd. That gives the administrator a choice to assign the right compression algorithm based on processing power, storage savings, and time to get the best out of the data stored in the datasets.

As far as the David vs Goliath tale goes, this real life use case was indeed a good one to share.

 

Discovering OpenZFS Fusion Pool

Fusion Pool excites me, but unfortunately this new key feature of OpenZFS is hardly talked about. I would like to introduce the Fusion Pool feature as iXsystems™ expands the TrueNAS® Enterprise storage conversations.

I would not say that this technology is revolutionary. Other vendors already have the similar concept of Fusion Pool. The most notable (to me) is NetApp® Flash Pool, and I am sure other enterprise storage vendors have the same. But this is a big deal (for me) for an open source file system in OpenZFS.

What is Fusion Pool  (aka ZFS Allocation Classes)?

To understand Fusion Pool, we have to understand the basics of the ZFS zpool. A zpool is the aggregation (borrowing the NetApp® terminology) of vdevs (virtual devices), and vdevs are a collection of physical drives configured with the OpenZFS RAID levels (RAID-0, RAID-1, RAID-Z1, RAID-Z2, RAID-Z3 and a few nested RAID permutations). A zpool can start with one vdev, and new vdevs can be added on-the-fly, expanding the capacity of the zpool online.

There are several types of vdevs prior to Fusion Pool, and this is as of pre-TrueNAS® version 12.0. As shown below, these are the types of vdevs available to the zpool at present.

OpenZFS zpool and vdev types – Credit: Jim Salter and Arstechnica

Fusion Pool is a zpool that integrates with a new, special type of vdev, alongside other normal vdevs. This special vdev is designed to work with small data blocks between 4-16K, and is highly efficient in handling random reading and writing of these small blocks. This bodes well with the OpenZFS file system metadata blocks and other blocks of small files. And the random nature of the Read/Write I/Os works best with SSDs (can be read or write intensive SSDs).

Continue reading

OpenZFS 2.0 exciting new future

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

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

OpenZFS Developer Summit 2020 Logo

OpenZFS Developer Summit 2020 Logo

Exciting developments

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

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

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Falconstor Software Defined Data Preservation for the Next Generation

Falconstor® Software is gaining momentum. Given its arduous climb back to the fore, it is beginning to soar again.

Tape technology and Digital Data Preservation

I mentioned that long term digital data preservation is a segment within the data lifecycle which has merits and prominence. SNIA® has proved that this is a strong growing market segment through its 2007 and 2017 “100 Year Archive” surveys, respectively. 3 critical challenges of this long, long-term digital data preservation is to keep the archives

  • Accessible
  • Undamaged
  • Usable

For the longest time, tape technology has been the king of the hill for digital data preservation. The technology is cheap, mature, and many enterprises has built their long term strategy around it. And the pulse in the tape technology market is still very healthy.

The challenges of tape remain. Every 5 years or so, companies have to consider moving the data on the existing tape technology to the next generation. It is widely known that LTO can read tapes of the previous 2 generations, and write to it a generation before. The tape transcription process of migrating digital data for the sake of data preservation is bad because it affects the structural integrity and quality of the content of the data.

In my times covering the Oil & Gas subsurface data management, I have seen NOCs (national oil companies) with 500,000 tapes of all generations, from 1/2″ to DDS, DAT to SDLT, 3590 to LTO 1-7. And millions are spent to transcribe these tapes every few years and we have folks like Katalyst DM, Troika and more hovering this landscape for their fill.

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The Falcon to soar again

One of the historical feats which had me mesmerized for a long time was the 14-year journey China’s imperial treasures took to escape the Japanese invasion in the early 1930s, sandwiched between rebellions and civil wars in China. More than 20,000 pieces of the imperial treasures took a perilous journey to the west and back again. Divided into 3 routes over a decade and four years, not a single piece of treasure was broken or lost. All in the name of preservation.

Today, that 20,000 over pieces live in perpetuity in 2 palaces – Beijing Palace Museum in China and National Palace Museum Taipei in Taiwan

Digital data preservation

Digital data preservation is on another end of the data lifecycle spectrum. More often than not, it is not the part that many pay attention to. In the past 2 decades, digital data has grown so much that it is now paramount to keep the data forever. Mind you, this is not the data hoarding kind but to preserve the knowledge and wisdom which is in the digital content of the data.

[ Note: If you are interested to know more about Data -> Information -> Knowledge -> Wisdom, check out my 2015 article on LinkedIn ]

SNIA (Storage Networking Industry Association) conducted 2 surveys – one in 2007 and another in 2017 – called the 100 Year Archive, and found that the requirement for preserving digital data has grown multiple folds over the 10 years. In the end, the final goal is to ensure that the perpetual digital contents are

  • Accessible
  • Undamaged
  • Usable

All at an affordable cost. Therefore, SNIA has the vision that the digital content must transcend beyond the storage medium, the storage system and the technology that holds it.

The Falcon reemerges

A few weeks ago, I had the privilege to speak with Falconstor® Software‘s David Morris (VP of Global Product Strategy & Marketing) and Mark Delsman (CTO). It was my first engagement with Falconstor® in almost 9 years! I wrote a piece of Falconstor® in my blog in 2011.

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NetApp double stitching Data Fabric

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

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

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

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Dell EMC Isilon is an Emmy winner!

[ Disclosure: I was invited by GestaltIT as a delegate to their Storage Field Day 19 event from Jan 22-24, 2020 in the Silicon Valley USA. My expenses, travel, accommodation and conference fees were covered by GestaltIT, the organizer and I was not obligated to blog or promote the vendors’ technologies presented at this event. The content of this blog is of my own opinions and views ]

And the Emmy® goes to …

Yes, the Emmy® goes to Dell EMC Isilon! It was indeed a well deserved accolade and an honour!

Dell EMC Isilon had just won the Technology & Engineering Emmy® Awards a week before Storage Field Day 19, for their outstanding pioneering work on the NAS platform tiering technology of media and broadcasting content according to business value.

A lasting true clustered NAS

This is not a blog to praise Isilon but one that instill respect to a real true clustered, scale-out file system. I have known of OneFS for a long time, but never really took the opportunity to really put my hands on it since 2006 (there is a story). So here is a look at history …

Back in early to mid-2000, there was a lot of talks about large scale NAS. There were several players in the nascent scaling NAS market. NetApp was the filer king, with several competitors such as Polyserve, Ibrix, Spinnaker, Panasas and the young upstart Isilon. There were also Procom, BlueArc and NetApp’s predecessor Auspex. By the second half of the 2000 decade, the market consolidated and most of these NAS players were acquired.

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Green Storage? Meh!

Something triggered my thoughts a few days ago. A few of us got together talking about climate change and a friend asked how green was the datacenter in IT. With cloud computing booming, I would say that green computing isn’t really the hottest thing at present. That in turn, leads us to one of the most voracious energy beasts in the datacenter, storage. Where is green storage in the equation?

What is green?

Over the past decade, several storage related technologies were touted as more energy efficient. These include

  • Tape – when tapes are offline, they do not consume power and do not require cooling
  • Virtualization – Virtualization reduces the number of servers and desktops, and of course storage too
  • MAID (Massive Array of Independent Disks) – the arrays spin down the HDDs if idle for a period of time
  • SSD (Solid State Drives) – Compared to HDDs, SSDs consume much less power, and overall reduce the cooling needs
  • Data Footprint Reduction – Deduplication, compression and other technologies to reduce copies of data
  • SMR (Shingled Magnetic Recording) Drives – Higher areal density means less drives but limited by physics.

The largest gorilla in storage technology

HDDs still dominate the market and they are the biggest producers of heat and vibration in a storage array, along with the redundant power supplies and fans. Until and unless SSDs dominate, we have to live with the fact that storage disk drives are not green. The statistics from Statistica below forecasts that in 2021, the shipment of SSDs will surpass HDDs.

Today the areal density of HDDs have increased. With SMR (shingled magnetic recording), the areal density jumped about 25% more than the 1Tb/inch (Terabit per inch) in the CMR (conventional magnetic recording) drives. The largest SMR in the market today is 16TB from Seagate with 18TB SMR in the horizon. That capacity is going to grow significantly when EAMR (energy assisted magnetic recording) – which counts heat assisted and microwave assisted – drives enter the market next year. The areal density will grow to 1.6Tb/inch with a roadmap to 4.0Tb/inch. Continue reading

Commvault coming all together

[Disclosure: I was invited by Commvault as a Media person and Social Ambassador to their Commvault GO 2019 Conference and also a Tech Field Day eXtra delegate from Oct 13-17, 2019 in the Denver CO, USA. My expenses, travel, accommodation and conference fees were covered by Commvault, 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]

This trip to the Commvault GO conference was pretty much a mission to find answers to their Hedvig acquisition just a month ago. It was an unprecedented move for Commvault and I, as an industry observer and pundit, took the news positively. I wrote in my blog about Commvault’s big bet and I liked their boldness in their approach.

But the news did not bode well back here in Malaysia. The local technology news portal, Data Storage Asean picked up the news in a rather unconvinced way. 2 long time Commvault partners I spoke to were obviously unhappy because the acquisition made little sense to them on the back of closing of the Commvault Malaysia office just weeks before this with more unsettling rumours of the Commvault team in Asia Pacific. The broken trust and the fear of what the future held for the Commvault customers in Malaysia and in the region were riding along with me on this trip.

But I have seen the beginning of the Commvault transformation from the Commvault GO conferences I have attended since 2017. This is my 3rd Commvault GO and I ended Day 1 with good vibes.

Here were some of my highlights in the first day. Continue reading

Did Cloud Kill LTFS?

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