Category Archives: Data
The Thailand flood last year spelled disaster to the storage industry. We have already seen several big boys in the likes of HP, EMC and NetApp announcing the rise of prices because of the flood.
But the Chinese character of “crisis” (below) also spells opportunities; opportunities for Solid State Drives (SSDs) that is.
For those of us close to the ground, the market for spinning hard disk drives (HDDs) has certainly been challenging for the past few months, especially for smaller system providers like us. Without the leveraging powers of the bigger boys, we practically had to beg to buy HDDs, not to mention the fact that the price has practically doubled.
Before the Thailand flood crisis, the GB/$ of a 2TB HDD was 0.325 Malaysian ringgit per GB. That’s about 33 cents. Today, the price is about 55 cents per GB. In comparison, at least from my experience, the GB/$ of SSDs has gone down from $5.83 to $4.99.
I know some of you might pooh-pooh the price difference between a 2TB SATA/SAS and a 120GB SSD, partly because the SSD seems so expensive. But when you consider that doing the math, the SSDs is likely to be 50x faster (at worst average) and 200x faster (at best average) for applications requiring IOPS, this could mean that transactional applications are likely to be completed an average of 100x faster, with better response time, with lower latency. This will have a domino effect on other related applications, making the entire service request performing and completing faster. When we put a price to the transactional hours, for example $10/hour work, then we can see the cost savings coming from using SSDs in the storage.
Interestingly, a friend of mine asked me about the prominence of an all SSDs storage systems. I have written about all SSDs systems in the past, and also did a high overview of Pure Storage some time back. And a very interesting fact I recalled was these systems having massive amount of IOPS. Having plenty of IOPS helps because you do away with Automated Storage Tiering (AST) because you don’t have to tier your data, and you don’t have to pay for such a feature.
Yes, all-SSDs pure-play storage systems are gaining prominence and it’s time to take notice. Nimbus beat NetApp and HP 3PAR last year to win eBay with an all SSDs storage solution and other players such as Violin Memory Systems, Pure Storage, SolidFire and of course, Texas Memory Systems (aka RAMSAN). And they are attracting big names into their management portfolios and getting VC dollars of course.
The Thailand flood aftermath will probably take 6 months or more to return to its previous production capacity prior to the crisis and SSDs can take this window of opportunity in the crisis to surge ahead. And if this flood is going to be an annual thing for Thailand (God bless Thailand), HDD market is going to have a perennial problem. And SSDs is going to rise even faster.
I am a bit surprised that primary storage deduplication has not taken off in a big way, unlike the times when the buzz of deduplication first came into being about 4 years ago.
When the first deduplication solutions first came out, it was particularly aimed at the backup data space. It is now more popularly known as secondary data deduplication, the technology has reduced the inefficiencies of backup and helped sparked the frenzy of adulation of companies like Data Domain, Exagrid, Sepaton and Quantum a few years ago. The software vendors were not left out either. Symantec, Commvault, and everyone else in town had data deduplication for backup and archiving.
It was no surprise that EMC battled NetApp and finally won the rights to acquire Data Domain for USD$2.4 billion in 2009. Today, in my opinion, the landscape of secondary data deduplication has pretty much settled and matured. Practically everyone has some sort of secondary data deduplication technology or solution in place.
But then the talk of primary data deduplication hardly cause a ripple when compared a few years ago, especially here in Malaysia. Yeah, the IT crowd is pretty fickle that way because most tend to follow the trend of the moment. Last year was Cloud Computing and now the big buzz word is Big Data.
We are here to look at technologies to solve problems, folks, and primary data deduplication technology solutions should be considered in any IT planning. And it is our job as storage networking professionals to continue to advise customers about what is relevant to their business and addressing their pain points.
I get a bit cheesed off that companies like EMC, or HDS continue to spend their marketing dollars on hyping the trends of the moment rather than using some of their funds to promote good technologies such as primary data deduplication that solve real life problems. The same goes for most IT magazines, publications and other communications mediums, rarely giving space to technologies that solves problems on the ground, and just harping on hypes, fuzz and buzz. It gets a bit too ordinary (and mundane) when they are trying too hard to be extraordinary because everyone is basically talking about the same freaking thing at the same time, over and over again. (Hmmm … I think I am speaking off topic now .. I better shut up!)
We are facing an avalanche of data. The other day, the CEO of Nexenta used the word “data tsunami” but whatever terms used do not matter. There is too much data. Secondary data deduplication solved one part of the problem and now it’s time to talk about the other part, which is data in primary storage, hence primary data deduplication.
What is out there? Who’s doing what in term of primary data deduplication?
NetApp has their A-SIS (now NetApp Dedupe) for years and they are good in my books. They talk to customers about the benefits of deduplication on their FAS filers. (Side note: I am seeing more benefits of using data compression in primary storage but I am not going to there in this entry). EMC has primary data deduplication in their Celerra years ago but they hardly talk much about it. It’s on their VNX as well but again, nobody in EMC ever speak about their primary deduplication feature.
I have always loved Ocarina Networks ECO technology and Dell don’t give much hoot about Ocarina since the acquisition in 2010. The technology surfaced a few months ago in Dell DX6000G Storage Compression Node for its Object Storage Platform, but then again, all Dell talks about is their Fluid Data Architecture from the Compellent division. Hey Dell, you guys are so one-dimensional! Ocarina is a wonderful gem in their jewel case, and yet all their storage guys talk about are Compellent and EqualLogic.
Moving on … I ought to knock Oracle on the head too. ZFS has great data deduplication technology that is meant for primary data and a couple of years back, Greenbytes took that and made a solution out of it. I don’t follow what Greenbytes is doing nowadays but I do hope that the big wave of primary data deduplication will rise for companies such as Greenbytes to take off in a big way. No thanks to Oracle for ignoring another gem in ZFS and wasting their resources on pre-sales (in Malaysia) and partners (in Malaysia) that hardly know much about the immense power of ZFS.
But an unexpected source coming from Microsoft could help trigger greater interest in primary data deduplication. I have just read that the next version of Windows Server OS will have primary data deduplication integrated into NTFS. The feature will be available in Windows 8 and the architectural view is shown below:
The primary data deduplication in NTFS will be a feature add-on for Windows Server users. It is implemented as a filter driver on a per volume basis, with each volume a complete, self describing unit. It is cluster aware, and fully crash consistent on all operations.
The technology is Microsoft’s own technology, built from scratch and will be working to position Hyper-V as an strong enterprise choice in its battle for the server virtualization space with VMware. Mind you, VMware already has a big, big lead and this is just something that Microsoft must do-or-die to keep Hyper-V playing catch-up. Otherwise, the gap between Microsoft and VMware in the server virtualization space will be even greater.
I don’t have the full details of this but I read that the NTFS primary deduplication chunk sizes will be between 32KB to 128KB and it will be post-processing.
With Microsoft introducing their technology soon, I hope primary data deduplication will get some deserving accolades because I think most companies are really not doing justice to the great technologies that they have in their jewel cases. And I hope Microsoft, with all its marketing savviness and adeptness, will do some justice to a technology that solves real life’s data problems.
I bid you good luck – Primary Data Deduplication! You deserved better.
My research on file systems brought me to an very interesting piece of article. It is titled “Dynamo: Amazon’s Highly Available Key-Value Store” dated 2007.
Yes, this is an internal storage systems designed and developed in Amazon to scale and support Amazon Web Services (AWS). It is a very complex piece of technology and the paper is highly technical (not for the faint of heart). And of all places, Amazon is probably the last place you think you would find such smart technology, but it’s true. AWS engineers are slowly revealing the many of their innovations (think Amazon Silk browser technology).
And it appears that many of the latest cloud-based computing and services companies such as Amazon, Google and many others have been developing new methods of storing data objects. These methods are very different from the traditional methods of storing data, and many are no longer adopting the relational database model (RDBMS) to scale their business.
The traditional 3-tier architecture often adopted by web-based (before the advent of “cloud”), is evolving. As shown in the diagram below:
the foundation tier is usually a relational database (or a distributed relational database), communicating with the back-end storage (usually a SAN).
All that is changing because the relational database model is not keeping up with the tremendous pace of the proliferation of web-based and cloud-based objects or unstructured data. As explained by Alex Iskold, a writer of ReadWriteWeb, there are scalability issues with the conventional relational database.
Before I get to the scalability issues mentioned in the above diagram, let me set the floor for discussion.
For theoretical schoolers of relational database, the term ACID defines and guarantees the transactional reliability of relational databases. ACID stands for Atomicity, Consistency, Isolation and Durability. According to Wikipedia, “transactions provide an “all-or-nothing” proposition, stating that each work-unit performed in a database must either complete in its entirety or have no effect whatsoever. Further, the system must isolate each transaction from other transactions, results must conform to existing constraints in the database, and transactions that complete successfully must get written to durable storage.”
ACID has been the cornerstone of relational database from the very beginning. But as the demands of greater scalability and greater distribution of data, all 4 components of ACID – Atomicity, Consistency, Isolation, Durability – can no longer hold true. Hence, the CAP Theorem.
CAP Theorem (aka Brewer’s Theorem) stands for Consistency, Availability and Partition Tolerance. In the ACM (Association of Computing Machinery) conference in 2000, Eric Brewer of University of California, Berkeley delivered the theorem. It states that it is impossible for a distributed computer system (or a database system) to simultaneously guarantee all 3 components – Consistency, Availability and Partition Tolerance.
Therefore, as the database systems become more and more distributed in cyberspace, the ACID theorem begins to break down. All 4 components of ACID cannot be guaranteed simultaneously anymore as the database systems begin to become more and more distributed.
So when we get back to the diagram, both the concepts on left and right – Master/Slave OR Multiple Peers – will put a tremendous strain on the single, non-distributed relational database.
New data models are surfacing to handling the very distributed data sets. Distributed object-based ”file systems” and NoSQL type of databases are some of the unconventional data storage “systems” that are beginning to surface as viable alternatives to the relational database method in cyberspace. And one of them is the Amazon Dynamo Storage System. (ADSS)
ADSS is a highly available, Amazon-proprietary key-value distributed data store. ADSS has both the properties of distributed hash table and a database and it is used internally to power various Cloud Services in Amazon Web Services (AWS).
It behaves like a relational database where it stores data objects to be retrieved. However, the data objects are not stored in a table format of a conventional relational database. Instead, the data is stored in a distributed hash table and data content or value is retrieved with a key, hence a key-value data model.
- Physical nodes are thought of as identical and organized into a ring.
- Virtual nodes are created by the system and mapped onto physical nodes, so that hardware can be swapped for maintenance and failure.
- The partitioning algorithm is one of the most complicated pieces of the system, it specifies which nodes will store a given object.
- The partitioning mechanism automatically scales as nodes enter and leave the system.
- Every object is asynchronously replicated to N nodes.
- The updates to the system occur asynchronously and may result in multiple copies of the object in the system with slightly different states.
- The discrepancies in the system are reconciled after a period of time, ensuring eventual consistency.
- Any node in the system can be issued a put or get request for any key
The Dynamo architecture addresses the CAP Theorem well. It is highly available, where nodes, either physical or virtual, can be easily swapped without affected the storage services. It is also high performance, nodes (again physical or virtual) can be added to boost the performance. The high performance and highly available components addresses the “A” piece of CAP.
Its distributed nature also allows it to scale to billions and billions of data objects and hence meets the “P” requirement of CAP. The Partitioning Tolerance is definitely there.
However, as stated by CAP Theorem, you can’t have all 3 happening at the same time. Therefore, the “C” or Consistency piece of CAP has to be compromised. That is why Dynamo has been labeled an “eventually consistency” storage system.
As data is stored into ADSS, the changes of the data is propogated and will be asynchronously replicated to other nodes in the system, eventually making all the data objects and its value consistent. However, given the speed of things in cyberspace and the nature of most Cloud Computing services, the consistency piece could be difficult to accomplish and that is OK because in most of the transactions that are distributed, inconsistency is acceptable.
So that’s a bit about the Amazon Dynamo. Alas, we may never get our grubby hands on this piece of cool data storage and management technology, but knowing that Dynamo is powering AWS and its business is an eye-opener for us into the realm of a new technology evolution.
I was in Singapore last week attending the Cloud Infrastructure Services course.
In the class, one of the foundation components of Cloud Computing is of course, storage. As the students and the instructor talked about Storage, one very interesting argument surfaced. It revolved around the storage, if it was offered on the cloud. A lot of people assumed that Cloud Storage would be for their databases, and their virtual machines, which of course, is true when the communication between the applications, virtual machines and databases are in the local area network of the Cloud Service Provider (CSP).
However, if the storage is offered through the cloud to applications that are sitting on-premise in the customer’s server room, then we have to think twice of how we perceive Cloud Storage. In this aspect, the Cloud Storage offered by the CSP is a Infrastructure-as-a-Service (IaaS), where the key service is Storage. We have to differentiate that this Storage functions as a data container, and usually not for I/O performance reasons.
Though this concept probably will be easily understood by storage professionals like us, this can cause a bit confusion for someone new to the concept of Cloud Computing and Cloud Storage. This confusion, unfortunately, is caused by many of us who are vendors or solution providers, or even publications and magazines. We are responsible to disseminate correct information to customers, but due to our lack of knowledge and experience in this extremely new market of Cloud Storage, we have created the FUDs (Fear, Uncertainty and Doubt) and hype.
Therefore, it is the duty of this blogger to clear the vapourware, and hopefully pass on the right information to accelerate the adoption of Cloud Storage in the near future. At this moment, given the various factors such as network costs, high network latency and lack of key network technologies similar to LAN in Cloud Computing, Cloud Storage is, most of the time, for data storage containership and archiving only. And there are no IOPS or any performance related statistics related to Cloud Storage. If any engineer or vendor tells you that they have the fastest Cloud Storage in the industry, do me a favour. Give him/her a knock on the head for me!
Of course, as technologies evolve, this could change in the near future. For now, Cloud Storage is a container, NOT a high performance storage in the cloud. It is usually not meant for transactional data. There are many vendors in the Cloud Storage space from real CSPs to storage companies offering re-packaged storage boxes that are “cloud-ready”. A good example of a CSP offering Cloud Storage is Amazon S3 (Simple Storage Service). And storage vendors such as EMC and HDS are repackaging and rebranding their storage technologies as object storage, ready for the cloud. EMC Atmos is really a repackaged and rebranded Centera, with some slight modifications, while HDS , using their Archiving solution, has HCP (aka HCAP). There’s nothing wrong with what EMC and HDS have done, but before the overhyping of the world of Cloud Computing, these platforms were meant for immutable data archiving reasons. Just thought you should know.
One particular company that captured my imagination and addresses the storage performance portion is Nasuni. Of course, they are quite inventive with the Cloud Storage Gateway approach. Nasuni comes up with a Cloud Storage Gateway filer appliance, which can be either a physical 1U server or as a VMware or Hyper-V virtual appliance sitting on-premise at the customer’s site.
The key to this is “on-premise”, which allows access to data much faster because they are locally-cached in the Nasuni filer appliance itself. This Nasuni filer piece addresses the Cloud Storage “performance” piece but Nasuni do not claim any performance statistics with such implementation. The clever bit is that this addresses data or files that are transactional in nature, i.e. NFS or CIFS, to serve data or files “locally”. (I wonder if Nasuni filer has iSCSI as well. Hmmmm….)
In the Nasuni architecture, they “break up” their “Cloud Storage” into 2 pieces. Piece #1 sits on-premise, at the customer site, and acts as a bridge to the Piece #2, that is sitting in a Cloud Storage. From a simplified view, have a look at the diagram below:
Piece #1 is the component that handles some of the transactional traffic related to files. In a more technical diagram below, you can see that the Nasuni filer addresses the file sharing portion, using the local disks on the filer appliance as a local caching mechanism.
Furthermore, older file pieces are whiffed away to the any Cloud Storage using the Cloud Connector interface, hence giving the customer a sense that their storage capacity needs can be limitless if they want to (for a fee, of course). At the same time, the Nasuni filer support thin provisioning and snapshots. How cool is that!
The Cloud Storage piece (Piece #2) is used for the data container and archiving reasons. This component can be sitting and hosted at Amazon S3, Microsoft Azure, Rackspace Cloud Files, Nirvanix Storage Delivery Network and Iron Mountain Archive Services Platform.
The data communication and transfer between the Nasuni filer is secure, encrypted, deduplication and compressed, giving it the efficiency and security that most customers would be concerned about. The diagram below explains the dat communication and data transfer bit.
In this manner, the Nasuni filer can replace traditional NAS platforms and can potentially provide a much lower total cost of ownership (TCO) in the long run. Nasuni does not pretend to be a NAS replacement. To me, this concept is very inventive and could potentially change the way we perceive file sharing and file server, obscuring and blurring concept of NAS.
Again, I would like to reiterate that Nasuni does not attempt to say their solution is a NAS or a performance-based Cloud Storage but what they have cleverly packaged seems to be appealing to customers. Their customer base has grown 78% in Q2 of 2011. It’s just too bad they are not here in Malaysia or this part of the world (yet).
IOPS in Cloud Storage? Not yet.
By now, I believe most of you in the storage networking world would have heard of Hadoop. Hadoop was created by Doug Cutting, while he and his team was working on an open source web search engine called Nutch. The easily recognized little yellow elephant, Hadoop, was Doug Cutting’s son toy, which he made as Hadoop’s mascot. Pretty cool!
And today, Hadoop has become THE platform for Big Data applications. Why?
As I have mentioned before, everything that we do or don’t do, generates data, either as a direct product or in-direct product. I am blogging right now and I am creating data. I was in Singapore the whole of this week and everywhere I go in the MRT stations, I am being watched by the video cameras they have at the station. A new friend in class said that Singapore is the second most “watched” city after London, where there are video cameras mounted everywhere, either discreetly or indiscreetly. And that’s just video data. And there’s plenty of other human activities that generate tons and tons of data.
IDC Digital Universe Report for 2011 said that we have generated 1.8ZB (zettabyte) of data this year alone. I mentioned in my previous blog that this is a gold mine and companies are scrambling to tap on massive amount of data. Extracting valuable information to anticipate the next trend or predict that next evolution in human preference is akin to the Gold Rush in the wild, wild west in the late 19th century. Folks, Big Data is going to be this generation’s “Digital Gold Rush”.
Sieving, filtering and processing gazillions of data (more unstructured than structured) will not work in defined, well-formatted relational databases. The data model of relational databases will simply break down. And of course, there are different schools of thoughts of different data models, but the Hadoop model seems to be gaining momentum and mind share of data scientists. That is because of Hadoop’s capability to deal with massive unstructured data, processing it and producing results in a small amount of time.
One way to process the pool of massive data is parallel programming. In parallel programming, multi-threading is commonly deployed to achieve the performance and effects of programming. But implementing multi-threading in parallel programming is difficult. Developers often has to deal with LWP (lightweight processes), semaphores, shared memory, mutex (mutually exclusive) locking and so on. Hence this style of programming works with different states on shared data, often resulting in different results in different states, even when using the same programming expression.
Hadoop belongs to another school of programming known as functional programming, where the different states on shared data concept is removed. With that in mind, the dependency on different states is also removed, resulting in a much easier and simpler parallel programming implementation. Hadoop borrows ideas from the MapReduce software framework made well known by Google and the Google File System.
Before, we get to know Hadoop, we must know MapReduce. MapReduce is a framework which allows very large data sets to be processed with a very large set of computer nodes in a cluster. Typically the computational processing is executed in a distributed fashion, spread across many computer nodes and final results are consolidated from the sub-results of these distributed processing nodes.
According to Wikipedia, the 2 key functions of Map Reduce are map() and reduce(). That’s pretty obvious. The extract below was taken from the Wikipedia definition, and explains both functions very well.
“Map” step: The master node takes the input, partitions it up into smaller sub-problems, and distributes them to worker nodes. A worker node may do this again in turn, leading to a multi-level tree structure. The worker node processes the smaller problem, and passes the answer back to its master node.
“Reduce” step: The master node then collects the answers to all the sub-problems and combines them in some way to form the output – the answer to the problem it was originally trying to solve.
The diagram below probably can simplify the concept of MapReduce to the readers.
Hadoop is one of the open-source implementations of MapReduce. It is one of the projects of Apache Foundation, and the project has sparked a brand-new niche of data search, data management and data science. The diagram below will allow our readers to juxtapose MapReduce and Hadoop, and comparing them in the simplest fashion.
Hadoop primary development platform is Java. Hadoop’s architecture consists mainly of 2 components – Hadoop Common and a Hadoop-compatible file system, as shown in the diagram below.
Hadoop MapReduce layer above is the file/object access interface to the Hadoop-compatible file system below. HDFS is Hadoop Distributed File System is just one of a few Hadoop-compatible file systems. Other file systems include:
- Amazon S3 File System as part of the Amazon EC2 Infrastructure-as-a-Service (IaaS) cloud platform
- CloudStore – a similar Hadoop-like implementation using C++ and also inspired by Google File System
- FTP file systems
- HTTP and HTTPS read-only file systems
- Any file systems accessible with the file:// URL nomenclature
But the main engine of Hadoop is in the MapReduce layer. The 2 core components in this layer is JobTracker and TaskTracker. Both has their own individual roles to play and collectively, they are key cogs in the Hadoop distributed data processing model.
Below are extract I picked up from Wikipedia.
JobTracker submits MapReduce jobs to client applications. The JobTracker pushes work out to available TaskTracker nodes in the cluster, striving to keep the work as close to the data as possible. With a rack-aware filesystem, the JobTracker knows which node contains the data, and which other machines are nearby. If the work cannot be hosted on the actual node where the data resides, priority is given to nodes in the same rack. This reduces network traffic on the main backbone network. If a TaskTracker fails or times out, that part of the job is rescheduled. The TaskTracker on each node spawns off a separate Java Virtual Machine process to prevent the TaskTracker itself from failing if the running job crashes the JVM. A heartbeat is sent from the TaskTracker to the JobTracker every few minutes to check its status. The Job Tracker and TaskTracker status and information is exposed by Jetty and can be viewed from a web browser. Jetty is a Java-based HTTP server, among other things
JobTracker records what it is up to in the filesystem. When a JobTracker starts up, it looks for any such data, so that it can restart work from where it left off.
By default Hadoop uses first-in, first-out (FIFO), and optional 5 scheduling priorities to schedule jobs from a work queue. In version 0.19 the job scheduler was refactored out of the JobTracker, and added the ability to use an alternate scheduler (such as the Fair scheduler or the Capacity scheduler).
The fair scheduler was developed by Facebook. The goal of the fair scheduler is to provide fast response times for small jobs and QoS (Quality of Service) for production jobs. The fair scheduler has three basic concepts.
- Jobs are grouped into Pools.
- Each pool is assigned a guaranteed minimum share.
- Excess capacity is split between jobs.
By default jobs that are uncategorized go into a default pool. Pools have to specify the minimum number of map slots, reduce slots, and a limit on the number of running jobs.
The capacity scheduler was developed by Yahoo. The capacity scheduler supports several features which are similar to the fair scheduler.
- Jobs are submitted into queues.
- Queues are allocated a fraction of the total resource capacity.
- Free resources are allocated to queues beyond their total capacity.
- Within a queue a job with a high level of priority will have access to the queue’s resources.
I took most the extract below from Wikipedia, and I don’t claim to be a knowledgeable person on Hadoop. All the credits go to Wikipedia editors to put Hadoop in layman terms.
Hadoop has certainly won the hearts of the new digital gold rush, Big Data and is slowly becoming a force to be reckoned with among data scientists. Hadoop implementations are powering new frontiers in processing and mining the ever growing data capacity, giving solution providers a simple programming methodology and data model to gain more insights into the vast seas of data and information.
Hadoop has many fans, and slowly becoming the data platform for large companies such as Yahoo!, Facebook, IBM, Amazon, Apple, eBay and many more. Facebook even claims to have the largest Hadoop clusters in the world, growing to 30PB in July of 2011.
This little yellow elephant is going places and one to watch out for.
Nowadays, the capacity of the hard disk drives (HDDs) are really big. 3TB is out and 4TB is in the horizon. What’s next?
For small-medium businesses in Malaysia, depending on their data requirements and applications, 3-10TB is pretty sufficient and with room to grow as well. Therefore, a 6TB requirement can be easily satisfied with 2 x 3TB HDDs.
If I were the customer, why would I buy a storage array, with the software licenses and other stuff that will not only increase my cost of equipment acquisition and data management, it will also increase the complexity of my IT infrastructure? I could just slot HDDs into my existing server, RAID it with RAID-0 (not a good idea but to save costs, most customers would do that) and I have a 6TB volume! It’s cheaper, easier to manage with Windows or Linux, and my system administrator doesn’t have to fuss about lack of storage experience.
And RAID isn’t really keeping up with the tremendous growth of HDD’s capacity as well. In fact, RAID is at risk. RAID (especially RAID 5/6) just cannot continue provide the LUN or volume reliability and data availability because it just takes too damn long to rebuild the volume after the failure of a disk.
Back in the days where HDDs were less than 500GB, RAID-5 would still hold up but after passing the 1TB mark, RAID-6 became more prevalent. But now, that 1TB has ballooned to 3TB and RAID-6 is on shaky ground. What’s next? RAID-7? ZFS has RAID-Z3, triple parity but come on, how many vendors have that? With triple parity or stronger RAID (is there one?), the price of the storage array is going to get too costly.
Experts have been speaking about parity-declustering, but that’s something that a few vendors have right now. Panasas, founded by one of forefathers of RAID, Garth Gibson, comes to mind. In fact, Garth Gibson and Mark Holland of Cargenie-Mellon University’s Parallel Data Lab (PDL) presented a paper about parity-declustering more than 10 years ago.
Let’s get back to our storage fatty. Yes, our storage is getting fat, obese, rotund or whatever you want to call it. And storage vendors have been pushing a concept in hope that storage administrators and customers can take advantage of it. It is called Storage Optimization or Storage Efficiency.
Here are a few ways you can consider to put your storage on a diet.
- Thin Provisioning
- Storage Tiering
- Tapes and SSDs
The storage train is still chugging hard and fast as IDC just released its Worldwide Disk Storage System Tracker for 3Q11. Despite the economic climate, the storage market posted a strong 8.5% revenue growth and a whopping 30.7% growth in terms of petabytes shipped. In total, 5,429PB were shipped in Q3.
So how did everyone do in this latest Tracker report?
In the Worldwide Total External Disk Storage Systems, EMC is still holding on to the #1 position, with 28.6%. IBM and NetApp came in at 12.7% and 12.1% respectively. The table below summarizes the percentage view of the top storage players, in terms of revenue.
From the table, everyone benefited from the strong buying of storage in the last quarter. EMC gained a strong market gain of almost 3%, while everyone else either gained or lost less than 1% market share. But the more interesting numbers are not from the market share column but the % growth column.
HDS posted the strongest growth of 22.1%, slightly higher than EMC of 22.0%. HDS is beginning to get their story right, putting the right storage solutions in place, and has been strongly focused in their services offering as well. That’s simply great news for HDS because this is a company is not known for their marketing and advertising. The Japanese “culture” within HDS probably has taught it to be prudent but to see HDS growing faster than the big boys like IBM and HP is something their competitors should respect. I believe customers are beginning to see the true potential of HDS.
As for EMC, everyone labels them as the 800-pound gorilla but they have been very nimble and strong in the storage market for many quarters. This is due to the strong management team headed by Joe Tucci and his heir-in-waiting, Pat Gelsinger. Several of their acquisitions are doing well, with the likes of Isilon, Greenplum, Data Domain, and of course VMware. Even though VMware does not contribute the EMC revenue numbers, the very fact that EMC owns more than 80% of VMware has already given EMC a lot of credibility in the storage battlefield. They are certainly going great guns.
NetApp took a hit in the last quarter, when they missed the street revenue numbers last quarter. Their stock took a beating and there were rumours in the market that NetApp might acquire Commvault and Quantum to compete with EMC. EMC has been able to leverage the list of companies and acquired solutions very well, from data protection solutions like Networker and Avamar, deduplication solutions like Data Domain and Avamar, Documentum for content management and so on, while NetApp has been, for the longest time, prefer a more “loosely-coupled” approach with their partners for a more complete solution set.
Other interesting reports from IDC are the Open SAN/NAS market, the NAS market and the iSCSI market.
The Open SAN/NAS market combination, according to IDC goes like this:
In the NAS only market, EMC and Isilon (under the one EMC umbrella) competes with NetApp and the table is like this:
The iSCSI only market is led by Dell (EqualLogic and Compellent combined), followed by EMC and IBM. Here’s the summarized table:
The strong growth is indeed good news as the storage market continues to weather the economic crisis storm. I have been saying this all along. The storage market in IT is still the growth engine as data keeps growing and growing, even though it was never the darling of the IT industry. Let’s hope the trend continues.
At the Internet Alliance event this morning, someone from Computerworld gave me a copy of their latest issue. The headline was “Security Incidents Soar”, with the details of the half-year review by CyberSecurity Malaysia.
Typically, the usual incidents list evolve around spam, intrusions, frauds, viruses and so on. However, storage always seems to be missing. As I see it, storage security doesn’t sit well with the security guys. In fact, storage is never the sexy thing and it is usually the IPS, IDS, anti-virus and firewall that get the highlights. So, when we talk about storage security, there is so little to talk about. In fact, in my almost 20-years of experience, storage security was only brought up ONCE!
In security, the most valuable piece of asset is data and no matter where the data goes, it always lands on …. STORAGE! That is why storage security could be one of the most overlooked piece in security. Fortunately, SNIA already has this covered. In SNIA’s Solid State Storage Initiative (SSSI), one aspect that was worked on was Self Encrypted Drives (SED).
SED is not new. As early as 2007, Seagate already marketed encrypted hard disk drives. In 2009, Seagate introduced enterprise-level encrypted hard disk drives. And not surprisingly, other manufacturers followed. Today, Hitachi, Toshiba, Samsung, and Western Digital have encrypted hard disk drives.
But there were prohibitive factors that dampened the adoption of self-encrypted drives. First of all, it was the costs. It was expensive a few years ago. There was (and still is) a lack of knowledge between the hardware of Self Encrypted Drives (SED) and software-based encryption. As the SED were manufactured, some had proprietary implementations that did not do their part to promote the adoption of SEDs.
As data travels from one infrastructure to another, data encryption can be implemented at different points. As the diagram below shows,
encryption can be put in place at the software level, the OS level, at the HBA, the network itself. It can also happen at the switch (network or fabric), at the storage array controller or at the hard disk level.
EMC multipathing software, PowerPath, has an encryption facility to ensure that data is encryption on its way from the HBA to the EMC CLARiiON storage controllers.
The “bump-in-the-wire” appliance is a bridge device that helps in composing encryption to the data before it reaches the storage. Recall that NetApp had a FIPS 140 certified product called Decru DataFort, which basically encrypted NAS and SAN traffic en-route to the NetApp FAS storage array.
And according to SNIA SSSI member, Tom Coughlin, SED makes more sense that software-based security. How does SED work?
First of all, SED works with 2 main keys:
- Authentication Key (AK)
- Drive Encryption Key (DEK)
Data security is already at its highest alert and SEDs are going to be a key component in the IT infrastructure. The open and common standards are coming together, thanks to efforts to many bodies including SNIA. At the same time, product certifications are coming up and more importantly, the price of SED has come to the level that it is almost on par with normal, non-encrypted drives.
Hackers and data thieves are getting smarter all the time and yet, the security of the most important place of where the data rest is the least considered. SNIA and other bodies hope to create more awareness and seek greater adoption of self encrypted drives. We hope you will help spread the word too. Betcha thinking twice now about encrypting your data on your disk drives now.
Good morning, afternoon, evening, Ladies & Gentlemen, wherever you are.
Today, we are going to learn how to bake, errr … I mean, make a storage performance model. Before we begin, allow me to set the stage.
Don’t you just hate it when you are asked to do storage performance sizing and you don’t have a freaking idea how to get started? A typical techie would probably say, “Aiya, just use the capacity lah!”, and usually, they will proceed to size the storage according to capacity. In fact, sizing by capacity is the worst way to do storage performance modeling.
Bear in mind that storage is not a black box, although some people wished it was. It is not black magic when it comes to performance sizing because things can be applied in a very scientific and logical manner.
SNIA (Storage Networking Industry Association) has made a storage performance modeling methodology (that’s quite a mouthful), and basically simplified it into these few key ingredients. This recipe is for storage performance modeling in general and I am advising you guys out there to engage your storage vendors professional services. They will know their storage solutions best.
And I am going to say to you – Don’t be cheap and not engage professional services – to get to the experts out there. I was having a chat with an consultant just now at McDonald’s. I have known this friend of mine for about 6-7 years now and his name is Sugen Sumoo, the Director of DBORA Consulting. They specialize in Oracle and database performance tuning and performance forecasting and it is something that a typical DBA can’t do, because DBORA Consulting is the Professional Service that brings expertise and value to Oracle customers. Likewise, you have to engage your respective storage professional services as well.
In a cook book or a cooking show, you are presented with the ingredients used and in this recipe for storage performance modeling, the ingredients (in no particular order) are:
- Application block size
- Read and Write ratio
- Application access patterns
- Working set size
- IOPS or throughput
- Demand intensity
Application Block Size
First of all, the storage is there to serve applications. We always have to look from the applications’ point of view, not storage’s point of view. Different applications have different block size. Databases typically range from 8K-64K and backup applications usually deal with larger block sizes. Video applications can have 256K block sizes or higher. It all depends.
The best way is to find out from the DBA, email administrator or application developers. The unfortunate thing is most so-called technical people or administrators in Malaysia doesn’t have a clue about the applications they manage. So, my advice to you storage professionals, do your research on the application and take the default value. These clueless fellas are likely to take the default.
Read and Write ratio
Applications behave differently at different times of the day, and at different times of the month (no, it’s not PMS). At the end of the financial year or calendar, there are some tasks that these applications do as well. But in a typical day, there are different weightage or percentage of read operations versus write operations.
Most OLTP (online transaction processing)-based applications tend to be read heavy and write light, but we need to find out the ratio. Typically, it can be a 2:1 ratio or 60%:40%, but it is best to speak to the application administrators about the ratio. DSS (Decision Support Systems) and data warehousing applications could have much higher reads than writes while a seismic-analysis applications can have multiple writes during the analysis periods. It all depends.
To counter the “clueless” administrators, ask lots of questions. Find out the workflow of several key tasks and ask what that particular tasks do at different checkpoints of the application’s processing. If you are lazy (please don’t be lazy, because it degrades your value as a storage professional), use a rule of thumb.
Application access patterns
Applications behave differently in general. They can be sequential, like backup or video streaming. They can be random like emails, databases at certain times of the day, and so on. All these behavioral patterns affect how we design and size the disks in the storage.
Some RAID levels tend to work well with sequential access and others, with random access. It is not difficult to find out about the applications’ pattern and if you read more about the different RAID-levels in storage, you can easily identify the type of RAID levels suitable for each type of behavioral patterns.
Working set size
This variable is a bit more difficult to determine. This means that a chunk of the application has to be loaded into a working area, usually memory and cache memory, to be used and abused by the application users.
Unless someone is well versed with the applications, one would not be able to determine how much of the applications would be placed in memory and in cache memory. Typically, this can only be determined after the application has been running for some time.
The flexibility of having SSDs, especially the DRAM-type of SSDs, are very useful to ensure that there is sufficient “working space” for these applications.
IOPS or Throughput
According to SNIA model, for I/O less than 64K, IOPS should be used as a yardstick to do storage performance modeling. Anything larger, use throughput, in which MB/sec is the measurement unit.
The application guy would be able to tell you what kind of IOPS their application is expecting or what kind of throughput they want. Again, ask a lot of questions, because this will help you determine the type of disks and the kind of performance you give to the application guys.
If the application guy is clueless again, ask someone more senior or ask the vendor. If the vendor engineers cannot give you an answer, then they should not be working for the vendor.
This part is usually overlooked when it comes to performance sizing. Demand intensity refers to how intense is the I/O requests. It could come from 1 channel or 1 part of the applications, or it could come from several parts of the applications in parallel. It is as if the storage is being ‘bombarded’ by applications and this is the part that is hard to determine as well.
In some applications, the degree of intensity or parallelism can be tuned and to find out, ask the application administrator or developer. If not, ask the vendor. Also do a lot of research on the application’s architecture.
And one last thing. What I have learned is to add buffers to the storage performance model. Typically I would add about 10-20% extra but you never know. As storage professionals, I would strongly encourage to engage professional services, because it is worthwhile, especially in the early stages of the sizing. It is usually a more expensive affair to size it after the applications have been installed and running.
“Failure to plan is planning to fail”. The recipe isn’t that difficult. Go figure it out.
ex·tra·or·di·naire - Outstanding or remarkable in a particular capacity
I was plucking the Internet after dinner while I am holidaying right now in Port Dickson. And at about this time, the news from my subscriptions will arrive, perfectly timed as my food is digesting.
And in the news – “IDC Says Cloud Adoption Fuels Storage Sales”. You think?
We are generating so much data in this present moment, that IDC is already saying that we are doubling our data every 2 years. That’s massive and a big part of it is being fueled our adoption to Cloud. It doesn’t matter if it is a public, private or hybrid cloud because the way we use IT has changed forever. It’s all too clear.
Amazon has a massive repository of contents; Google has been gobbling tons of data and statistics since its inception; Apple has made IT more human; and Facebook has changed the way we communicate. FastCompany magazine called Amazon, Apple, Google and Facebook the Big 4 and they will converge sooner or later into what the tornado chasers call a Perfect Storm. Every single effort that these 4 companies are doing now will inevitably meet at one point, where content, communication, computing, data, statistics all become the elements of the Perfect Storm. And the outcome of this has never been more clearer. As FastCompany quoted:
“All of our activity on these devices produces a wealth of data, which leads to the third big idea underpinning their vision. Data is like mother’s milk for Amazon, Apple, Facebook, and Google. Data not only fuels new and better advertising systems (which Google and Facebook depend on) but better insights into what you’d like to buy next (which Amazon and Apple want to know). Data also powers new inventions: Google’s voice-recognition system, its traffic maps, and its spell-checker are all based on large-scale, anonymous customer tracking. These three ideas feed one another in a continuous (and often virtuous) loop. Post-PC devices are intimately connected to individual users. Think of this: You have a family desktop computer, but you probably don’t have a family Kindle. E-books are tied to a single Amazon account and can be read by one person at a time. The same for phones and apps. For the Fab Four, this is a beautiful thing because it means that everything done on your phone, tablet, or e-reader can be associated with you. Your likes, dislikes, and preferences feed new products and creative ways to market them to you. Collectively, the Fab Four have all registered credit-card info on a vast cross-section of Americans. They collect payments (Apple through iTunes, Google with Checkout, Amazon with Amazon Payments, Facebook with in-house credits). Both Google and Amazon recently launched Groupon-like daily-deals services, and Facebook is pursuing deals through its check-in service (after publicly retreating from its own offers product).”
Cloud is changing the way we work, we play, we live and data is now the currency of humans in the developed and developing worlds. And that is good news for us storage professionals, because all the data has to eventually end up in a storage somewhere, somehow.
That is why there is a strong demand for storage networking professionals. Not just any storage professionals but the ones that have the right attitude to keep developing themselves, enhancing their skillset, knowledge and experience. The ones that can forsee that the future will worship them and label them as deities of the Cloud era.
So why are you guys take advantage of this? Well, don’t just sit there and be ordinary. Be a storage extraordinaire now! And for those guys who want to settle of being ordinary … too bad! I said this before – You could lose your job.
Happy school holidays!