Tony Pearson is a Master Inventor and Senior IT Architect for the IBM Storage product line at the
IBM Executive Briefing Center in Tucson Arizona, and featured contributor
to IBM's developerWorks. In 2016, Tony celebrates his 30th year anniversary with IBM Storage. He is
author of the Inside System Storage series of books. This blog is for the open exchange of ideas relating to storage and storage networking hardware, software and services.
(Short URL for this blog: ibm.co/Pearson )
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“In times of universal deceit, telling the truth will be a revolutionary act.”
-- George Orwell
Well, it has been over two years since I first covered IBM's acquisition of the XIV company. Amazingly, I still see a lot of misperceptions out in the blogosphere, especially those regarding double drive failures for the XIV storage system. Despite various attempts to [explain XIV resiliency] and to [dispel the rumors], there are still competitors making stuff up, putting fear, uncertainty and doubt into the minds of prospective XIV clients.
Clients love the IBM XIV storage system! In this economy, companies are not stupid. Before buying any enterprise-class disk system, they ask the tough questions, run evaluation tests, and all the other due diligence often referred to as "kicking the tires". Here is what some IBM clients have said about their XIV systems:
“3-5 minutes vs. 8-10 hours rebuild time...”
-- satisfied XIV client
“...we tested an entire module failure - all data is re-distributed in under 6 hours...only 3-5% performance degradation during rebuild...”
-- excited XIV client
“Not only did XIV meet our expectations, it greatly exceeded them...”
In this blog post, I hope to set the record straight. It is not my intent to embarrass anyone in particular, so instead will focus on a fact-based approach.
Fact: IBM has sold THOUSANDS of XIV systems
XIV is "proven" technology with thousands of XIV systems in company data centers. And by systems, I mean full disk systems with 6 to 15 modules in a single rack, twelve drives per module. That equates to hundreds of thousands of disk drives in production TODAY, comparable to the number of disk drives studied by [Google], and [Carnegie Mellon University] that I discussed in my blog post [Fleet Cars and Skin Cells].
Fact: To date, no customer has lost data as a result of a Double Drive Failure on XIV storage system
This has always been true, both when XIV was a stand-alone company and since the IBM acquisition two years ago. When examining the resilience of an array to any single or multiple component failures, it's important to understand the architecture and the design of the system and not assume all systems are alike. At it's core, XIV is a grid-based storage system. IBM XIV does not use traditional RAID-5 or RAID-10 method, but instead data is distributed across loosely connected data modules which act as independent building blocks. XIV divides each LUN into 1MB "chunks", and stores two copies of each chunk on separate drives in separate modules. We call this "RAID-X".
Spreading all the data across many drives is not unique to XIV. Many disk systems, including EMC CLARiiON-based V-Max, HP EVA, and Hitachi Data Systems (HDS) USP-V, allow customers to get XIV-like performance by spreading LUNs across multiple RAID ranks. This is known in the industry as "wide-striping". Some vendors use the terms "metavolumes" or "extent pools" to refer to their implementations of wide-striping. Clients have coined their own phrases, such as "stripes across stripes", "plaid stripes", or "RAID 500". It is highly unlikely that an XIV will experience a double drive failure that ultimately requires recovery of files or LUNs, and is substantially less vulnerable to data loss than an EVA, USP-V or V-Max configured in RAID-5. Fellow blogger Keith Stevenson (IBM) compared XIV's RAID-X design to other forms of RAID in his post [RAID in the 21st Centure].
Fact: IBM XIV is designed to minimize the likelihood and impact of a double drive failure
The independent failure of two drives is a rare occurrence. More data has been lost from hash collisions on EMC Centera than from double drive failures on XIV, and hash collisions are also very rare. While the published worst-case time to re-protect from a 1TB drive failure for a fully-configured XIV is 30 minutes, field experience shows XIV regaining full redundancy on average in 12 minutes. That is 40 times less likely than a typical 8-10 hour window for a RAID-5 configuration.
A lot of bad things can happen in those 8-10 hours of traditional RAID rebuild. Performance can be seriously degraded. Other components may be affected, as they share cache, connected to the same backplane or bus, or co-dependent in some other manner. An engineer supporting the customer onsite during a RAID-5 rebuild might pull the wrong drive, thereby causing a double drive failure they were hoping to avoid. Having IBM XIV rebuild in only a few minutes addresses this "human factor".
In his post [XIV drive management], fellow blogger Jim Kelly (IBM) covers a variety of reasons why storage admins feel double drive failures are more than just random chance. XIV avoids load stress normally associated with traditional RAID rebuild by evenly spreading out the workload across all drives. This is known in the industry as "wear-leveling". When the first drive fails, the recovery is spread across the remaining 179 drives, so that each drive only processes about 1 percent of the data. The [Ultrastar A7K1000] 1TB SATA disk drives that IBM uses from HGST have specified 1.2 million hours mean-time-between-failures [MTBF] would average about one drive failing every nine months in a 180-drive XIV system. However, field experience shows that an XIV system will experience, on average, one drive failure per 13 months, comparable to what companies experience with more robust Fibre Channel drives. That's innovative XIV wear-leveling at work!
Fact: In the highly unlikely event that a DDF were to occur, you will have full read/write access to nearly all of your data on the XIV, all but a few GB.
Even though it has NEVER happened in the field, some clients and prospects are curious what a double drive failure on an XIV would look like. First, a critical alert message would be sent to both the client and IBM, and a "union list" is generated, identifying all the chunks in common. The worst case on a 15-module XIV fully loaded with 79TB data is approximately 9000 chunks, or 9GB of data. The remaining 78.991 TB of unaffected data are fully accessible for read or write. Any I/O requests for the chunks in the "union list" will have no response yet, so there is no way for host applications to access outdated information or cause any corruption.
(One blogger compared losing data on the XIV to drilling a hole through the phone book. Mathematically, the drill bit would be only 1/16th of an inch, or 1.60 millimeters for you folks outside the USA. Enough to knock out perhaps one character from a name or phone number on each page. If you have ever seen an actor in the movies look up a phone number in a telephone booth then yank out a page from the phone book, the XIV equivalent would be cutting out 1/8th of a page from an 1100 page phone book. In both cases, all of the rest of the unaffected information is full accessible, and it is easy to identify which information is missing.)
If the second drive failed several minutes after the first drive, the process for full redundancy is already well under way. This means the union list is considerably shorter or completely empty, and substantially fewer chunks are impacted. Contrast this with RAID-5, where being 99 percent complete on the rebuild when the second drive fails is just as catastrophic as having both drives fail simultaneously.
Fact: After a DDF event, the files on these few GB can be identified for recovery.
Once IBM receives notification of a critical event, an IBM engineer immediately connects to the XIV using remote service support method. There is no need to send someone physically onsite, the repair actions can be done remotely. The IBM engineer has tools from HGST to recover, in most cases, all of the data.
Any "union" chunk that the HGST tools are unable to recover will be set to "media error" mode. The IBM engineer can provide the client a list of the XIV LUNs and LBAs that are on the "media error" list. From this list, the client can determine which hosts these LUNs are attached to, and run file scan utility to the file systems that these LUNs represent. Files that get a media error during this scan will be listed as needing recovery. A chunk could contain several small files, or the chunk could be just part of a large file. To minimize time, the scans and recoveries can all be prioritized and performed in parallel across host systems zoned to these LUNs.
As with any file or volume recovery, keep in mind that these might be part of a larger consistency group, and that your recovery procedures should make sense for the applications involved. In any case, you are probably going to be up-and-running in less time with XIV than recovery from a RAID-5 double failure would take, and certainly nowhere near "beyond repair" that other vendors might have you believe.
Fact: This does not mean you can eliminate all Disaster Recovery planning!
To put this in perspective, you are more likely to lose XIV data from an earthquake, hurricane, fire or flood than from a double drive failure. As with any unlikely disaster, it is best to have a disaster recovery plan than to hope it never happens. All disk systems that sit on a single datacenter floor are vulnerable to such disasters.
For mission-critical applications, IBM recommends using disk mirroring capability. IBM XIV storage system offers synchronous and asynchronous mirroring natively, both included at no additional charge.
This week, I was reminded that back in 2011, Watson beat two human players, Ken Jennings and Brad Rutter on the TV game show "Jeopardy!" On his last response, Ken wrote "I for one welcome our new computer overlords." With IBM investing heavily in Cognitive Solutions, should people be worried, or welcome the new technology?
Back in 1950, Isaac Asimov proposed "Three laws of robots":
A robot may not injure a human being or, through inaction, allow a human being to come to harm.
A robot must obey orders given it by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
Let's take a look at how Artificial Intelligence has been represented in the movies over the past few decades. I have put these in chronological order when they were initially released in the United States.
(FCC Disclosure and Spoiler Alert: I work for IBM. This blog post can be considered a "paid celebrity endorsement" for cognitive solutions made by IBM. While IBM may have been involved or featured in some of these movies, I have no financial interest in them. I have seen them all and highly recommend them. I am hoping that you have all seen these, or at least familiar enough with their plot lines that I am not spoiling them for you.)
2001: A Space Odyssey
Back in 1968, Stanley Kubrick and Arthur C. Clarke made a masterpiece movie about a mysterious obelisk floating near Jupiter. To investigate, a crew of human beings takes a space ship managed by a sentient computer named [HAL-9000].
(Many people thought HAL was a subtle reference to IBM. Stanley Kubrick clarifies:
"By the way, just to show you how interpretation can sometimes be bewildering: A cryptographer went to see the film, and he said, 'Oh. I get it. Each letter of HAL's name is one letter ahead of IBM. The H is one letter in front of I, the A is one letter in front of B, and the L is one letter in front of M.'
Now this is a pure coincidence, because HAL's name is an acronym of heuristic and algorithmic, the two methods of computer programming...an almost inconceivable coincidence. It would have taken a cryptographer to have noticed that."
Source: The Making of 2001: A Space Odyssey, Eye Magazine Interview, Modern Library, pp. 249)
The problem arises when HAL-9000 refuses commands from the astronauts. The astronauts are not in control, HAL-9000 was given separate orders from ground control back on earth, and it has determined it would be more successful without the crew.
In 1973, Michael Crichton wrote and directed this movie about an amusement park with three uniquely themed areas: Medieval World, Roman World, and Westworld. Robots are used to staff the parks to make them more realistic, interacting with the guests in character appropriate for each time period.
A malfunction spreads like a computer virus among the robots, causing them to harm or kill the park's guests. Yul Brenner played a robot called simply "the Gunslinger". Equipped with fast reflexes and infrared vision, the Gunslinger proves especially deadly!
(Michael Crichton also wrote "Jurassic Park", which had a similar story line involving dinosaurs with catastrophic results!)
Last year, HBO launched a TV series called "Westworld", based on the same themes covered in this movie. The first season of 10 episodes just finished, and the next season is scheduled for 2018.
Directed by Ridley Scott, this 1982 movie stars Harrison Ford as Rick Deckard, a law enforcement officer. Rick is tasked to hunt down and "retire" four cognitive androids named "replicants" that have killed some humans and are now in search of their creator, a man named J. F. Sebastian.
(I enjoy the euphemisms used in these movies. Terms like kill, murder or assassinate apply to humans but not machines. The word "retire" in this movie refers to destruction of the robots. As we say in IBM, "retirement is not something you do, it is something done to you!")
Destroying machines does not carry the same emotional toll as killing humans, but this movie explores that empathy. A sequel called "Blade Runner 2049" will be released later this year.
In 1983, Matthew Broderick plays David, a young high school student who hacks into the U.S. Military's War Operation Plan Response (WOPR) computer. The WOPR was designed to run various strategic games, including war game simulations, learning as it goes. David decides to initiate the game "Global Thermonuclear War", and the military responds as if the threats were real.
Can the computer learn that the only way to win a war is not to wage it in the first place? And if a computer can learn this, can our human leaders learn this too?
In this series of movies, a franchise spanning from 1984 to 2009, the US Military builds a defense grid computer called [Skynet]. After cognitive learning at an alarming rate, Skynet becomes self-aware, and decides to launch missiles, starting a nuclear war that kills over 3 billion people.
Arnold Schwarzenegger plays the Terminator model T-800, a cognitive solution in human form designed by Skynet to finish the job and kill the remainder of humanity.
In this 2004 movie, Will Smith plays Del Spooner, a technophobic cop who investigates a crime committed by a cognitive robot.
(Many people associate the title with author Isaac Asimov. A short story called "I, Robot" written by Earl and Otto Binder was published in the January 1939 issue of 'Amazing Stories', well before the unrelated and more well-known book 'I, Robot' (1950), a collection of short stories, by Asimov.
Asimov admitted to being heavily influenced by the Binder short story. The title of Asimov's collection was changed to "I, Robot" by the publisher, against Asimov's wishes. Source: IMDB)
Del Spooner uncovers a bigger threat to humanity, not just a single malfunctioning robot, but rather the Virtual Interactive Kinesthetic Interface, or simply VIKI for short, a cognitive solution that controls all robots. VIKI interprets Asimov's three laws in a manner not originally intended.
In this 2015 movie, Domhnall Gleeson plays Caleb, a 26 year old programmer at the world's largest internet company. Caleb wins a competition to spend a week at a private mountain retreat. However, when Caleb arrives he discovers that he must interact with Ava, the world's first true artificial intelligence, a beautiful robot played by Alicia Vikander.
(The title derives from the Latin phrase "Deus Ex-Machina," meaning "a god from the Machine," a phrase that originated in Greek tragedies. Sources: IMDB)
Nathan, the reclusive CEO of this company, relishes this opportunity to have Caleb participate in this experiment, explaining how Artificial Intelligence (AI) will transform the world.
(The three main characters all have appropriate biblical names. Ava is a form of Eve, the first woman; Nathan was a prophet in the court of David; and Caleb was a spy sent by Moses to evaluate the Promised Land. Source: IMDB)
The premise is based in part on the famous [Turing Test], developed by Alan Turing. This is designed to test a machine's ability to exhibit intelligent behavior equivalent to, or indistinguishable from, that of a human.
Movies that depict the bad guys as a particular nationality, ethnicity or religion may be offensive to some movie audiences. Instead, having dinosaurs, monsters, aliens or robots provides a villain that all people can fear equally. This helps movie makers reach a more global audience!
Of course, if robots, androids and other forms of Artificial Intelligence did exactly what humans expect them to, we would not have the tense, thrilling action movies to watch on the big screen.
This is not a complete list of movies. Enter in the comments below your favorite movie that features Artificial Intelligence and why it is your favorite!
Last month, I had the pleasure to help train Watson in its latest mission, to help answer questions from sellers, this are not just for the IBM feet on the street, but also for IBM distributors and IBM Business Partners as well.
"... [survey by SearchYourCloud] revealed 'workers took up to 8 searches to find the right document and information.' Here are a few other statistics that help tell the tale of information overload and wasted time spent searching for correct information -- either external or internal:
'According to a McKinsey report, employees spend 1.8 hours every day -- 9.3 hours per week, on average -- searching and gathering information. Put another way, businesses hire 5 employees but only 4 show up to work; the fifth is off searching for answers, but not contributing any value.' Source: [Time Searching for Information]
'19.8 percent of business time -- the equivalent of one day per working week -- is wasted by employees searching for information to do their job effectively,' according to Interact. Source: [A Fifth of Business Time is Wasted]
IDC data shows that 'the knowledge worker spends about 2.5 hours per day, or roughly 30 percent of the workday, searching for information ... 60 percent [of company executives] felt that time constraints and lack of understanding of how to find information were preventing their employees from finding the information they needed.' Source: [Information: The Lifeblood of the Enterprise]."
In the early days of the Internet, before search engines like Google or Bing, I competed in [Internet Scavenger Hunts]. A dozen or more contestants would be in a room, and would be given a list of 20 questions to find answers for. Each of us would then hunt down answers on the Internet. The person to find the most documented answers before time runs out wins. It was quite the challenge!
Over the years, I have honed my skills as a [Search Ninja]. With over 30 years of experience in IBM Storage, many sellers come to me for answers. Sometimes sellers are just too lazy to look for the answers themselves, too busy trying to meet client deadlines, or too green to know where to look.
A good portion of my 60-hour week is spent helping sellers find the answers they are looking for. Sometimes I dig into the [SSIC], product data sheets, or various IBM Redbooks.
Other times, I would confer with experts, engineers and architects in particular development teams. Often, I learn something new myself. In a few cases, I have turned some questions into ideas for blog posts!
It was no surprise when I was asked to help train Watson for the new "Systems SmartSeller" tool. This will be a tool that runs on smartphones or desktops to help answer questions that sellers might need to respond to RFP or other client queries.
The premise was simple. Treat Watson as a student at "Cognitive University" taking classes from dozens of IBM professors, in a series of semesters, or "phases".
Phase I involved building the "Corpus", the set of documents related to z Systems, POWER systems, Storage and SDI solutions; and a "Grading Tool" that would be used as the Graphical User Interface. I was not involved in phase I.
Phase II was where I came in. Hundreds of questions are categorized by product area. I worked on 500 questions for storage. For each question, Watson had up to eleven different responses, typically a paragraph from the Corpus. My job as a professor was to grade the responses to some 500 storage questions:
★ (one star)
Irrelevant, answer not even storage-related
★★ (two stars)
Relevant, at least it is storage-related, but does not answer the question, or answers it poorly
★★★ (three stars)
Relevant, adequately answers the question
★★★★ (four stars)
Relevant, answers the question well
Most of the answers were either 1-star (not storage related) or 2-star (mentioned storage, but poor response). I would search through the existing Corpus looking for a better answer, and at best found only 3-star responses, which I would add to the list and grade as a 3-star response.
I then searched the Internet for better answers. Once I found a good match, I would type up a 4-star response, add it to the list, and point it to the appropriate resources on the Web.
Other professors, who were also looking at these questions, would then get to grade my suggested responses as well. Watson would learn based on the consensus of how appropriate and accurate each response was graded.
I don't know where the Cognitive University team got some of the questions, but they were quite representative of the ones I get every week. In some cases, the seller didn't understand the question he heard from the client, making it difficult for me to figure out what they were actually asking for.
It reminds me of that parlor game ["Telephone" or "Chinese Whispers"], in which one person whispers a message to the ear of the next person through a line of people until the last player announces the message to the entire group. I have actually played this at an IBM event in China!
Watson needs to parse the question into nouns and verbs, and use that Natural Linguistic Programming (NLP) to then search the Corpus for appropriate answer. I determined three challenges for Watson in this case:
The questions are not always fully formed sentences. For example, "Object storage?" Is this asking what is object storage in general, or rather what does IBM offer in this area?
The questions often do not spell the names of products correctly, or use informal abbreviations. "Can Store-wise V7 do RtC?" is a typical example, short for "Can the IBM Storwize V7000 storage controller perform Real-time Compression?"
The questions ask what is planned in the future. "When will IBM offer feature x in product y?" I am sorry, but Watson is not [Zoltar, the fortune teller]!
I managed to grade the responses in the two weeks we were given. Part of my frustration was the grading tool itself was a bit buggy, and I spent some time trying to track down some of its flaws.
The next phase is in late January and February. This will give the Cognitive University team a chance to update the Corpus, improve the grading interface, and find more professors and different set of questions. I volunteered the most recent four years' worth of my blog posts to be added to the Corpus.
Maybe this tool will help me turn my 60-hour week back to the 40-hour week it should be!
Well, it's Tuesday again, and you know what that means? IBM Announcements!
(OK, yes, today is Friday, but I was busy getting married on Tuesday, so IBM pushed the announcements out one day to Wednesday, and technically I am writing this blog post during my honeymoon vacation, so the IBM marketing team and my new wife both cut me some slack. Work/Life balance is all about compromises, right?)
IBM DS8880 Storage System
The IBM DS8880 comes in three models, the DS8884 entry level, the DS8886 enterprise level, and the DS8888 all-flash array. IBM offers 1, 2, 3 and 4 year warranties.
The new High Performance Flash Enclosure (HPFE) Gen2 delivers more capacity than Gen1. The 2U flash enclosures are configured in pairs with each enclosure supporting up to twenty-four 2.5-inch flash cards in capacities 400 GB, 800 GB, 1.6 TB and 3.2 TB.
The HPFE Gen2 are currently available for both the DS8884 and DS8886 models. The maximum flash capacity for the DS8886 increases from 96 TB to 614.4 TB, delivering reduced storage costs through lesser cost per IOPS with this new flash enclosure. IBM has made a statement of direction to offer these HPFE Gen2 on the DS8888 as well.
To improve security, IBM DS8880 now supports customer-defined digital certificates for authentication, and configurable Hardware Management Console (HMC) firewall support.
For IBM's mainframe clients, IBM now offers "Extents-level" space release support for z/OS®, DSCLI (Command Line Interface) support for z/OS environment, and FICON® Information Unit (IU) pacing improvements.
IBM Spectrum Virtualize™ V7.8 delivers support for the latest SAN Volume Controller, FlashSystem V9000 and Storwize® product family, and adds new software functionality and improvements
In conjunction with [IBM Spectrum Copy Data Management], Spectrum Virtualize v7.8 offers flexible data protection with transparent cloud tiering to leverage the cloud as FlashCopy targets and restore these snapshots from the cloud on select platforms.
However, the encryption keys are kept on USB thumb drives, which are either left in the USB ports on the back of the hardware, or locked away in a safe, only to be retrieved as needed when rebooting the systems or upgrading the firmware.
Now, IBM Spectrum Virtualize v7.8 supports the IBM Security Key Lifecycle Manager (SKLM) to manage encryption keys. IBM continues to support USB thumb drives if you prefer, but SKLM is used to manage keys for most of the rest of IBM products, and provides centralized management.
The SVC and Storwize models can directly attach via 12Gb SAS to expansion drawers. At the time, we supported 2U-high 12-bay that support Large Form Factor (LFF) 3.5-inch Nearline (7200 rpm) drives, and 2U-high 24-bay that support the Small Form Factor (SFF) 2.5-inch drives (SSD, 15K, 10K and 7200 rpm).
With Spectrum Virtualize v7.8, IBM now offers a third option, the 5U-high 92-bay that supports both LFF and SFF drives. This new expansion can be attached to Storwize V5000 Gen2, Storwize V7000 (models 524/Gen2 and 624/Gen2+), and SVC (models DH8 and SV1).
For the 12-bay and 92-bay, IBM now supports 10TB capacity 3.5-inch Nearline drives. For the 24-bay and 92-bay, IBM now supports 7.68 TB and 15.36 TB capacity Solid State Drives (SSD).
For those concerned about the phrase "lower endurance" in the press release, let me explain. SSD have a bit of extra capacity included. If you write the full capacity of the drive every day for a year, you will "burn up" about one percent of the capacity.
To handle ten "Full Drive Writes per Day" (10 FDWP) over the course of five years, IBM adds 50 percent extra spare capacity above the 400 GB, 800 GB, 1.6 TB and 3.2 TB capacities. So, a 400GB full-endurance drive is really 600 GB inside. These were sometimes referred to as "Enterprise" SSD.
For the larger device sizes, the IT industry has determined that 1 FDWP is sufficient, so instead of 50 percent spare capacity, IBM adds only 5 percent extra. The 7.68 TB is really 8.06 TB inside. These were earlier referred to as "Read-Intensive" SSD. These come in 1.92 TB, 3.84 TB, 7.68 TB and 15.36 TB capacities.
IBM is also offering non-disruptive model conversions. Storwize V5010 can now be converted to V5020, and V5020 can be converted to V5030. The Storwize V7000 Model 524 (Gen2) can be converted to model 624 (Gen2+).
The DeepFlash 150 is the perfect JBOF addition to the ESS family. The current ESS models had either 2U-high 24-drive bays, or 4U-high 60-drive bays. This new model is 3U-high with 64 high-capacity (8 TB) Board Solid State Drives (BSSD).
The ESS includes all the features of IBM Spectrum Scale, including both 8+2 and 8+3 Erasure Coding data protection. This provides file and object access to data, including POSIX compliance for Windows, Linux and AIX operating systems, as well as HDFS-compliant access for big data analytics.