Category Archives: Appliance

Crash consistent data recovery for ZFS volumes

By | | , , , , , , , , , , , , , , , , , , , , , , ,
Leave a comment

While TrueNAS® CORE and TrueNAS® Enterprise are more well known for its NAS (network attached storage) prowess, many organizations are also confidently placing their enterprise applications such as hypervisors and databases on TrueNAS® via SANs (storage area networks) as well. Both iSCSI and Fibre Channel™ (selected TrueNAS® Enterprise storage models) protocols are supported well.

To reliably protect these block-based applications via the SAN protocols, ZFS snapshot is the key technology that can be dependent upon to restore the enterprise applications quickly. However, there are still some confusions when it comes to the state of recovery from the ZFS snapshots. On that matter, this situations are not unique to the ZFS environments because as with many other storage technologies, the confusion often stem from the (mis)understanding of the consistency state of the data in the backups and in the snapshots.

Crash Consistency vs Application Consistency

To dispel this misunderstanding, we must first begin with the understanding of a generic filesystem agnostic snapshot. It is a point-in-time copy, just like a data copy on the tape or in the disks or in the cloud backup. It is a complete image of the data and the state of the data at the storage layer at the time the storage snapshot was taken. This means that the data and metadata in this snapshot copy/version has a consistent state at that point in time. This state is frozen for this particular snapshot version, and therefore it is often labeled as “crash consistent“.

In the event of a subsystem (application, compute, storage, rack, site, etc) failure or a power loss, data recovery can be initiated using the last known “crash consistent” state, i.e. restoring from the last good backup or snapshot copy. Depending on applications, operating systems, hypervisors, filesystems and the subsystems (journals, transaction logs, protocol resiliency primitives etc) that are aligned with them, some workloads will just continue from where it stopped. It may already have some recovery mechanisms or these workloads can accept data loss without data corruption and inconsistencies.

Some applications, especially databases, are more sensitive to data and state consistencies. That is because of how these applications are designed. Take for instance, the Oracle® database. When an Oracle® database instance is online, there is an SGA (system global area) which handles all the running mechanics of the database. SGA exists in the memory of the compute along with transaction logs, tablespaces, and open files that represent the Oracle® database instance. From time to time, often measured in seconds, the state of the Oracle® instance and the data it is processing have to be synched to non-volatile, persistent storage. This commit is important to ensure the integrity of the data at all times.

Continue reading →

How well do you know your data and the storage platform that processes the data

By | | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Leave a comment

Last week was consumed by many conversations on this topic. I was quite jaded, really. Unfortunately many still take a very simplistic view of all the storage technology, or should I say over-marketing of the storage technology. So much so that the end users make incredible assumptions of the benefits of a storage array or software defined storage platform or even cloud storage. And too often caveats of turning on a feature and tuning a configuration to the max are discarded or neglected. Regards for good storage and data management best practices? What’s that?

I share some of my thoughts handling conversations like these and try to set the right expectations rather than overhype a feature or a function in the data storage services.

Complex data networks and the storage services that serve it

I/O Characteristics

Applications and workloads (A&W) read and write from the data storage services platforms. These could be local DAS (direct access storage), network storage arrays in SAN and NAS, and now objects, or from cloud storage services. Regardless of structured or unstructured data, different A&Ws have different behavioural I/O patterns in accessing data from storage. Therefore storage has to be configured at best to match these patterns, so that it can perform optimally for these A&Ws. Without going into deep details, here are a few to think about:

  • Random and Sequential patterns
  • Block sizes of these A&Ws ranging from typically 4K to 1024K.
  • Causal effects of synchronous and asynchronous I/Os to and from the storage

Continue reading →

Sassy Cato

By | | , , , , , , , , , , , , ,
Leave a comment

I am not cybersecurity guy at all. Cybersecurity, to me, is a hodgepodge of many things. It is complex and it is confusing. But to every organization that has to deal with cloud SaaS (software-as-a-service) applications, mobile devices, work from home, and the proliferation of network connections from everywhere to the edge and back, strong cybersecurity without the burden of sluggish performance and without the complexity of stitching the cybersecurity point solutions would be a god send.

About 3 1/2 years ago, when I was an independent consultant, I was asked by a friend to help him (I was also looking for a gig) sell a product. It was Aryaka Networks, an SD-WAN solution. It was new to me, although I had some MPLS (multi protocol label switching) knowledge from some point in my career. But the experience with Aryaka at the people level was not too encouraging, with several people I was dealing with, switching positions or leaving Aryaka, including their CEO at the time, John Peters. After about 4 months or so, my friend lost confidence and decided to switch to Cato Networks.

Cato Networks opened up my eyes to what I believe cybersecurity should be. Simple, performant, and with many of the previous point requirements like firewall, VPN, zero trust networks, identity management, intrusion prevention, application gateways, threat detection and response, remote access, WAN acceleration and several more, all beautifully crafted into a single cloud-based service. There was an enlightenment moment for a greenhorn like me as I learned more about the Cato solution. That singularity of distributed global networking and cybersecurity blew me away.

Continue reading →

What happened to NDMP?

By | | , , , , , , , , , , , , , , , , , , , , , , ,
Leave a comment

The acronym NDMP shows up once in a while in NAS (Network Attached Storage) upgrade tenders. And for the less informed, NDMP (Network Data Management Protocol) was one of the early NAS data management (more like data mover specifications) initiatives to backup NAS devices, especially the NAS appliances that run proprietary operating systems code.

NDMP Logo

Backup software vendors often have agents developed specifically for an operating system or an operating environment. But back in the mid-1990s, 2000s, the internal file structures of these proprietary vendors were less exposed, making it harder for backup vendors to develop agents for them. Furthermore, there was a need to simplify the data movements of NAS files between backup servers and the NAS as a client, to the media servers and eventually to the tape or disk targets. The dominant network at the time ran at 100Mbits/sec.

To overcome this, Network Appliance® and PDC Solutions/Legato® developed the NDMP protocol, allowing proprietary NAS devices to run a standardized client-server architecture with the NDMP server daemon in the NAS and the backup service running as an NDMP client. Here is a simplified look at the NDMP architecture.

NDMP Client-Server Architecture

Continue reading →

The Starbucks model for Storage-as-a-Service

By | | , , , , , , , , , , , , , , , , , , , , , , , , ,
Leave a comment

Starbucks™ is not a coffee shop. It purveys beyond coffee and tea, and food and puts together the yuppie beverages experience. The intention is to get the customers to stay as long as they can, and keep purchasing the Starbucks’ smorgasbord of high margin provisions in volume. Wifi, ambience, status, coffee or tea with your name on it (plenty of jokes and meme there), energetic baristas and servers, fancy coffee roasts and beans et. al. All part of the Starbucks™-as-a-Service pleasurable affair that intends to lock the customer in and have them keep coming back.

The Starbucks experience

Data is heavy and they know it

Unlike compute and network infrastructures, storage infrastructures holds data persistently and permanently. Data has to land on a piece of storage medium. Coupled that with the fact that data is heavy, forever growing and data has gravity, you have a perfect recipe for lock-in. All storage purveyors, whether they are on-premises data center enterprise storage or public cloud storage, and in between, there are many, many methods to keep the data chained to a storage technology or a storage service for a long time. The storage-as-a-service is like tying the cow to the stake and keeps on milking it. This business model is very sticky. This stickiness is also a lock-in mechanism.

Continue reading →

Open Source Storage Technology Crafters

By | | , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Leave a comment

The conversation often starts with a challenge. “What’s so great about open source storage technology?”

For the casual end users of storage systems, regardless of SAN (definitely not Fibre Channel) or NAS on-premises, or getting “files” from the personal cloud storage like Dropbox, OneDrive et al., there is a strong presumption that open source storage technology is cheap and flaky. This is not helped with the diet of consumer brands of NAS in the market, where the price is cheap, but the storage offering with capabilities, reliability and performance are found to be wanting. Thus this notion floats its way to the business and enterprise users, and often ended up with a negative perception of open source storage technology.

Highway Signpost with Open Source wording

Storage Assemblers

Anybody can “build” a storage system with open source storage software. Put the software together with any commodity x86 server, and it can function with the basic storage services. Most open source storage software can do the job pretty well. However, once the completed storage technology is put together, can it do the job well enough to serve a business critical end user? I have plenty of sob stories from end users I have spoken to in these many years in the industry related to so-called “enterprise” storage vendors. I wrote a few blogs in the past that related to these sad situations:

We have such storage offerings rigged with cybersecurity risks and holes too. In a recent Unit 42 report, 250,000 NAS devices are vulnerable and exposed to the public Internet. The brands in question are mentioned in the report.

I would categorize these as storage assemblers.

Continue reading →

The future of Fibre Channel in the Cloud Era

By | | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
3 Comments

The world has pretty much settled that hybrid cloud is the way to go for IT infrastructure services today. Straddled between the enterprise data center and the infrastructure-as-a-service in public cloud offerings, hybrid clouds define the storage ecosystems and architecture of choice.

A recent Blocks & Files article, “Broadcom server-storage connectivity sales down but recovery coming” caught my attention. One segment mentioned that the server-storage connectivity sales was down 9% leading me to think “Is this a blip or is it a signal that Fibre Channel, the venerable SAN (storage area network) protocol is on the wane?”

Fibre Channel Sign

Thus, I am pondering the position of Fibre Channel SANs in the cloud era. Where does it stand now and in the near future? Continue reading →

Where are your files living now?

By | | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Leave a comment

[ This is Part One of a longer conversation ]

EMC2 (before the Dell® acquisition) in the 2000s had a tagline called “Where Information Lives™“**. This was before the time of cloud storage. The tagline was an adage of enterprise data storage, proper and contemporaneous to the persistent narrative at the time – Data Consolidation. Within the data consolidation stories, thousands of files and folders moved about the networks of the organizations, from servers to clients, clients to servers. NAS (Network Attached Storage) was, and still is the work horse of many, many organizations.

[ **Side story ] There was an internal anti-EMC joke within NetApp® called “Information has a new address”.

EMC tagline “Where Information Lives”

This was a time where there were almost no concerns about Shadow IT; ransomware were less known; and most importantly, almost everyone knew where their files and folders were, more or less (except in Oil & Gas upstream – to be told in later in this blog). That was because there were concerted attempts to consolidate data, and inadvertently files and folders, in the organization.

Even when these organizations were spread across the world, there were distributed file technologies at the time that could deliver files and folders in an acceptable manner. Definitely not as good as what we have today in a cloudy world, but acceptable. I personally worked a project setting up Andrew File Systems for Intel® in Penang in the mid-90s, almost joined Tacit Networks in the mid-2000s, dabbled on Microsoft® Distributed File System with NetApp® and Windows File Servers while fixing the mountains of issues in deploying the worldwide GUSto (Global Unified Storage) Project in Shell 2006. Somewhere in my chronological listings, Acopia Networks (acquired by F5) and of course, EMC2 Rainfinity and NetApp® NuView OEM, Virtual File Manager.

The point I am trying to make here is most IT organizations had a good grip of where the files and folders were. I do not think this is very true anymore. Do you know where your files and folders are living today? 

Continue reading →

Enterprise Storage is not just a Label

By | | , , , , , , , , , , , , , , , , , , ,
3 Comments

I have many anecdotes around the topic of Enterprise Storage, but the conversations in the past 2 weeks made it important for me to share this.

Enterprise Storage is …

Amusing, painful, angry

I get riled up whenever people do not want to be educated about Enterprise Storage. Here are a few that happened in the last 2 weeks.

[ Story #1 ]

A guy was building his own storage for cryptocurrency. He was informed by his supplier that the RAID card was enterprise, and he could get the best performance using “Enterprise” RAID-0.

  • Well, “Enterprise” RAID-0 volume crashed, and he lost all data. Painfully, he said he lost a hefty sum financially

[ Story #2 ]

A media company complained about the reliability of previous storage vendor. The GM was shopping around and was told that there are “Enterprise” SATA drives and the reliability is as good, if not better than SAS drives.

  • The company wanted a fully reliable Enterprise Storage system with 99.999% availability, and yet the SATA interface was not meant to build a more highly reliable enterprise storage. The GM insisted to use “Enterprise” SATA drives for his “enterprise” storage system instead of SAS.  

[ Story #3 ]

An IT admin of a manufacturing company claimed that they had an “Enterprise Storage” system for a few years, and could not figure out why his hard disk drives would die every 12-15 months.

  • He figured out that the drives supplied by his vendor were consumer SATA drives, even though he was told it was an “Enterprise Storage” system when he bought the system.

Continue reading →

Plotting the Crypto Coin Storage Farm

By | | , , , , , , , , , , , , , , , , , ,
1 Comment

The recent craze of the Chia cryptocurrency got me excited. Mostly because it uses storage as the determinant for the Proof-of-Work consensus algorithm in a blockchain network. Yes, I am always about storage. 😉

I am not a Bitcoin miner nor am I a Chia coin farmer, and my knowledge and experience in both are very shallow. But I recently became interested in the 2 main activities of Chia – plotting and farming, because they both involved storage. I am writing this blog to find out more and document about my learning experience.

[ NB: This blog does not help you make money. It is just informational from a storage technology perspective. ]

Chia Cryptocurrency

Proof of Space and Time

Bitcoin is based on Proof-of-Work (PoW). In a nutshell, there is a complex mathematical puzzle to be solved. Bitcoin miners compete to solve this puzzle and the process uses high computational processing to solve it. Once solved, the miners are rewarded for their work.

Newer entrants like Filecoin and Chia coin (XCH) use an alternate method which is Proof-of-Space (PoS) to validate and verify the transactions. Instead of miners, Chia coin farmers have to prove to have a legitimate amount of disk and/or memory space to solve a mathematical puzzle, conceptually similar to the one in Bitcoin mining. In the beginning, this was great for folks who have unused disk space that can be “rented” out to store the crypto stuff (Note: I am not familiar with the terminology yet, and I did not want to use the word “crypto tokens” incorrectly). Storj was one of the early vendors that I remember in this space touting this method but I have not followed them for a while. Their business model might have changed.

Continue reading →