I am still wiping the coffee off my computer screen, inadvertently sprayed when I took a sip while reading HDS' uber-blogger Hu Yoshida's post on storage virtualization andvendor lock-in
. This blog appears to be the text version of theirfunny video
While most of the post is accurate and well-stated, two opinions particular caught my eye. I'll be nice and call them opinions, since these are blogs, and always subject to interpretation. I'll put quotes around them so that people will correctly relate these to Hu, and not me.
"Storage virtualization can only be done in a storage controller. Currently Hitachi is the only vendor to provide this."
-- Hu Yoshida
Hu, I enjoy all of your blog entries, but you should know better. HDS is fairly new-comer to the storage virtualization arena, so since IBM has been doing this for decades, I will bring you and the rest of the readers up to speed. I am not starting a blog-fight, just want to provide some additional information for clients to consider when making choices in the marketplace.
First, let's clarify the terminology. I will use 'storage' in the broad sense, including anything that can hold 1's and 0's, including memory, spinning disk media, and plastic tape media. These all have different mechanisms and access methods, based on their physical geometry and characteristics. The concept of 'virtualization' is any technology that makes one set of resources look like another set of resources with more preferable characteristics, and this applies to storage as well as servers and networks. Finally, 'storage controller' is any device with the intelligence to talk to a server and handle its read and write requests.
Second, let's take a look at all the different flavors of storage virtualization that IBM has developed over the past 30 years.
IBM introduces the S/370 with the OS/VS1 operating system. "VS" here refers to virtual storage, and in this case internal server memory was swapped out to physical disk. Using a table mapping, disk was made to look like an extension of main memory.
IBM introduces the IBM 3850 Mass Storage System (MSS). Until this time, programs that ran on mainframes had to be acutely aware of the device types being written, as each device type had different block, track and cylinder sizes, so a program written for one device type would have to be modified to work with a different device type. The MSS was able to take four 3350 disks, and a lot of tapes, and make them look like older 3330 disks, since most programs were still written for the 3330 format. The MSS was a way to deliver new 3350 disk to a 3330-oriented ecosystem, and greatly reduce the cost by handling tape on the back end. The table mapping was one virtual 3330 disk (100 MB) to two physical tapes (50 MB each). Back then, all of the mainframe disk systems had separate controllers. The 3850 used a 3831 controller that talked to the servers.
IBM invents Redundant Array of Independent Disk (RAID) technology. The table mapping is one or more virtual "Logical Units" (or "LUNs") to two or more physical disks. Data is striped, mirrored and paritied across the physical drives, making the LUNs look and feel like disks, but with faster performance and higher reliability than the physical drives they were mapped to. RAID could be implemented in the server as software, on top or embedded into the operating system, in the host bus adapter, or on the controller itself. The vendor that provided the RAID software or HBA did not have to be the same as the vendor that provided the disk, so in a sense, this avoided "vendor lock-in".Today, RAID is almost always done in the external storage controller.
IBM introduces the Personal Computer. One of the features of DOS is the ability to make a "RAM drive". This is technology that runs in the operating system to make internal memory look and feel like an external drive letter. Applications that already knew how to read and write to drive letters could work unmodified with these new RAM drives. This had the advantage that the files would be erased when the system was turned off, so it was perfect for temporary files. Of course, other operating systems today have this feature, UNIX has a /tmp directory in memory, and z/OS uses VIO storage pools.
This is important, as memory would be made to look like disk externally, as "cache", in the 1990s.
IBM AIX v3 introduces Logical Volume Manager (LVM). LVM maps the LUNs from external RAID controllers into virtual disks inside the UNIX server. The mapping can combine the capacity of multiple physical LUNs into a large internal volume. This was all done by software within the server, completely independent of the storage vendor, so again no lock-in.
IBM introduces the Virtual Tape Server (VTS). This was a disk array that emulated a tape library. A mapping of virtual tapes to physical tapes was done to allow full utilization of larger and larger tape cartridges. While many people today mistakenly equate "storage virtualization" with "disk virtualization", in reality it can be implemented on other forms of storage. The disk array was referred to as the "Tape Volume Cache". By using disk, the VTS could mount an empty "scratch" tape instantaneously, since no physical tape had to be mounted for this purpose.
Contradicting its "tape is dead" mantra, EMC later developed its CLARiiON disk library that emulates a virtual tape library (VTL).
IBM introduces the SAN Volume Controller. It involves mapping virtual disks to manage disks that could be from different frames from different vendors. Like other controllers, the SVC has multiple processors and cache memory, with the intelligence to talk to servers, and is similar in functionality to the controller components you might find inside monolithic "controller+disk" configurations like the IBM DS8300, EMC Symmetrix, or HDS TagmaStore USP. SVC can map the virtual disk to physical disk one-for-one in "image mode", as HDS does, or can also map virtual disks across physical managed disks, using a similar mapping table, to provide advantages like performance improvement through striping. You can take any virtual disk out of the SVC system simply by migrating it back to "image mode" and disconnecting the LUN from management. Again, no vendor lock-in.
The HDS USP and NSC can run as regular disk systems without virtualization, or the virtualization can be enabled to allow external disks from other vendors. HDS usually counts all USP and NSC sold, but never mention what percentage these have external disks attached in virtualization mode. Either they don't track this, or too embarrassed to publish the number. (My guess: single digit percentage).
Few people remember that IBM also introduced virtualization in both controller+disk and SAN switch form factors. The controller+disk version was called "SAN Integration Server", but people didn't like the "vendor lock-in" having to buy the internal disk from IBM. They preferred having it all external disk, with plenty of vendor choices. This is perhaps why Hitachi now offers a disk-less version of the NSC 55, in an attempt to be more like IBM's SVC.
IBM also had introduced the IBM SVC for Cisco 9000 blade. Our clients didn't want to upgrade their SAN switch networking gear just to get the benefits of disk virtualization. Perhaps this is the same reason EMC has done so poorly with its "Invista" offering.
So, bottom line, storage virtualization can, and has, been delivered in the operating system software, in the server's host bus adapter, inside SAN switches, and in storage controllers. It can be delivered anywhere in the path between application and physical media. Today, the two major vendors that provide disk virtualization "in the storage controller" are IBM and HDS, and the three major vendors that provide tape virtualization "in the storage controller" are IBM, Sun/STK, and EMC. All of these involve a mapping of logical to physical resources. Hitachi uses a one-for-one mapping, whereas IBM additionally offers more sophisticated mappings as well.
technorati tags: IBM, disk, tape, storage, virtualization, Hu Yoshia, HDS, Hitachi, TagmaStore, USP, NSC, disk-less, SAN Volume Controller, LVM, AIX, RAID, SAN, blade, Sun, STK, Cisco, EMC, Invista,
Last week, in my posting on Toshiba's latest 1.8" drive
, Robert Pearson asks:
You may not be the right person to ask but I am asking everyone so "How do you see hybrid disk drives?"
(For the record, I am not immediately related to Robert. At onepoint, "Pearson" was the 12th most common surname in the USA, but now doesn't even make the Top 100.)
Robert, I would like to encourage you and everyone else to ask questions, don't worry if I am the wrong person to ask, asprobably I know the right person within IBM. Some people have called me the "Kevin Bacon" of Storage,as I am often less than six degrees away from the right person, having worked in IBM Storage for over 20 years.
For those not familiar with hybrid drives, there is a good write-up in Wikipedia.
Unfortunately, most of the people I would consult on this question, such as those from Market Intelligence or Research, are on vacation for the holidays, so, Robert, I will have to rely on my trusted 78-card Tarot deck and answer you with a five-card throw.
- Your first card, Robert, is the Hermit. This card represents "introspection". The best I/O is no I/O, which means that if applications can keep the information they need inside server memory, you can avoid the bus bandwidth limitations to going to external storage devices. Where external storage makes sense is when data is shared between servers, or when the single server is limited to a set amount of internal memory. So, consider maxing out the memory in your server first (IBM would be glad to sell you more internal memory!!!), then consider outside solid-state or hybrid devices. Windows for example has an architectural limit of 4GB.
- Your second card, Robert, is the Four of Cups, representing "apathy".On the card, you see three cups together, with the fourth cup being delivered from a cloud. This reminds me thatwe have three storage tiers already (memory,disk,tape), and introducing a fourth tier into the mix may not garnermuch excitement. For the mainframe, IBM introduced a Solid-State Device, call the Coupling Facility, which can be accessed from multipleSystem z servers. It is used heavily by DFSMS and DB2 to hold shared information. However, given some customer's apathytowards Information Lifecycle Management which includes "tiered storage", introducing yet another tier that forcespeople to decide what data goes where may be another challenge.
- Your third card, Robert, is the Chariot, which represents "Speed, Determination,and Will". In some cases, solid state disk are faster for reading, but can be slower for writing. In the case of ahybrid drive, where the memory acts as a front-end cache, read-hits would be faster, but read-misses might be slower.While the idea of stopping the drives during inactivity will reduce power consumption, spinning up and slowing downthe disk may incur additional performance penalties. At the time of this post, the fastest disk system remains the IBM SAN Volume Controller, based on SPC-1 and SPC-2 benchmarks in excess of those published for other devices.
- Your fourth card, Robert, is the Eight of Pentacles, which represents"Diligence, Hard work". The pentacles are coins with five-sided stars on them, and this often represents money.Our research team has projected that spinning disk will continue to be a viable and profitable storage media for at least anothereight years.
- Your fifth and last card, Robert, is the World, which normallyrepresents "Accomplishment", but since it is turned upside down, the meaning is reversed to "Limitation". Some Hybriddisks, and some types of solid state memory in general, do have limitations in the number of write cycles they can handle. For thoseunhappy with the frequency and slowness for rebuilds on SATA disk may find similar problems with hybrid drives.For that reason, businesses may not trust using hybrid drives for their busiest, mission-critical applications, but certainlymight use it for archive data with lower write-cycle requirements.
The tarot cards are never wrong, but certainly interpretations of the cards can be.
technorati tags: Robert Pearson, Kevin Bacon, IBM, storage, Tarot, card, deck, Hermit, Four-of-Cups, Coupling Facility, Chariot, SAN Volume Controller, SVC, SPC-1, SPC-2, benchmarks, Texas Memory Systems, Eight-of-Pentacles, World, Hybrid, SATA
Jon Toigo has a funny cartoon on his post, [As I Listen to EMC Brag on “New” Functionality…
]. Basically, it pokes fun that many of us bloggers argue which vendor was first to introduce some technology or another. We all do this, myself included.
Recently, Claus Mikkelsen's, currently with HDS, [brought up accurately some past history from the 1990s], which is before many storage bloggers hired on with their current employers. Claus and I worked together for IBM back then, so I recognized many of the events he mentions that I can't talk about either. In many cases, IBM or HDS delivered new features before EMC.
I've been reading with some amusement as fellow blogger Barry Burke asked Claus a series of questions about Hitachi's latest High Availability Manager (HAM) feature. Claus was too busy with his "day job" and chose to shut Barry down. Sadly, HDS set themselves up for ridicule this round, first by over-hyping a function before its announcement, and then announcing a feature that IBM and EMC have offered for a while. The problem and confusion for many is that each vendor uses different terminology. Hitachi's HAM is similar to IBM's HyperSwap and EMC's AutoSwap. The implementations are different, of course, which is often why vendors are often asked to compare and contrast one implementation to another.
In his latest response,[how to mind the future of a mission-critical world], Barry reports that several HDS bloggers now censor his comments.That's too bad. I don't censor comments, within reason, including Barry's inane questions about IBM's products, and am glad that he does not censor my inane questions to him about EMC products in return. The entire blogosphere benefits from these exchanges, even if they are a bit heated sometimes.
We all have day jobs, and often are just too busy, or too lazy, to read dozens or hundreds of pages of materials, if we can even find them in the first place. Not everyone has the luxury of a "competitive marketing" team to help do the research for you, so if we can get an accurate answer or clarification about a product that is generally available directly from a vendor's subject matter expert, I am all for that.
technorati tags: IBM, Jon Toigo, HDS, Claus Mikkelsen, EMC, Barry Burke, HAM
It's official! My "blook" Inside System Storage - Volume I
is now available.
|This blog-based book, or “blook”, comprises the first twelve months of posts from this Inside System Storage blog,165 posts in all, from September 1, 2006 to August 31, 2007. Foreword by Jennifer Jones. 404 pages.|
- IT storage and storage networking concepts
- IBM strategy, hardware, software and services
- Disk systems, Tape systems, and storage networking
- Storage and infrastructure management software
- Second Life, Facebook, and other Web 2.0 platforms
- IBM’s many alliances, partners and competitors
- How IT storage impacts society and industry
You can choose between hardcover (with dust jacket) or paperback versions:
This is not the first time I've been published. I have authored articles for storage industry magazines, written large sections of IBM publications and manuals, submitted presentations and whitepapers to conference proceedings, and even had a short story published with illustrations by the famous cartoon writer[Ted Rall].
But I can say this is my first blook, and as far as I can tell, the first blook from IBM's many bloggers on DeveloperWorks, and the first blook about the IT storage industry.I got the idea when I saw [Lulu Publishing] run a "blook" contest. The Lulu Blooker Prize is the world's first literary prize devoted to "blooks"--books based on blogs or other websites, including webcomics. The [Lulu Blooker Blog] lists past year winners. Lulu is one of the new innovative "print-on-demand" publishers. Rather than printing hundredsor thousands of books in advance, as other publishers require, Lulu doesn't print them until you order them.
I considered cute titles like A Year of Living Dangerously, orAn Engineer in Marketing La-La land, or Around the World in 165 Posts, but settled on a title that matched closely the name of the blog.
In addition to my blog posts, I provide additional insights and behind-the-scenes commentary. If you go to the Luluwebsite above, you can preview an entire chapter in its entirety before purchase. I have added a hefty 56-page Glossary of Acronyms and Terms (GOAT) with over 900 storage-related terms defined, which also doubles as an index back to the post (or posts) that use or further explain each term.
So who might be interested in this blook?
- Business Partners and Sales Reps looking to give a nice gift to their best clients and colleagues
- Managers looking to reward early-tenure employees and retain the best talent
- IT specialists and technicians wanting a marketing perspective of the storage industry
- Mentors interested in providing motivation and encouragement to their proteges
- Educators looking to provide books for their classroom or library collection
- Authors looking to write a blook themselves, to see how to format and structure a finished product
- Marketing personnel that want to better understand Web 2.0, Second Life and social networking
- Analysts and journalists looking to understand how storage impacts the IT industry, and society overall
- College graduates and others interested in a career as a storage administrator
And yes, according to Lulu, if you order soon, you can have it by December 25.
technorati tags: IBM, blook, Volume I, Jennifer Jones, system, storage, strategy, hardware, software, services, disk, tape, networking, SAN, secondlife, Web2.0, facebook, Lulu, publishing, Blooker Prize, articles, magazines, proceedings, Ted Rall, insights, glossary, early-tenure, mentors, library, classroom, administrator, print, publish, on demand
In North America, today marks the start of the "Give 1 Get 1" program.
|Children using the XO laptop|
I first learned from this when I was reading about Timothy Ferriss' [LitLiberation project] on his [Four Hour Work Week] blog, and was surfing around for related ideas, and chanced upon this. I registered for a reminder, and it came today(the reminder, not the laptop itself).
Here's how the program works. You give $399 US dollars to the "One Laptop per Child" (OLPC)[laptop.org] organization for two laptops: One goes to a deserving child ina developing country, the second goes to you, for your own child, or to donate to a localcharity that helps children. This counts as a $199 purchase plus a $200 tax-deductible donation.For Americans, this is a [US 501(c)(3)] donation, and for Canadians and Mexicans, take advantage of the low-value of the US dollar!
If your employer matches donations, like IBM does, get them to match the $200donation for a third laptop, which goes to another child in a developing country. As for shipping, you pay only for the shipping of the one to you, each receiving country covers their own shipping. In my case, the shipping was another $24 US dollars for Arizona.No guarantees that it will arrive in time for the holidays this December, but it might.
To sweeten the deal, T-mobile throws in a year's worth of "Wi-Fi Hot Spot"that you can use for yourself, either with the XO laptop itself, or your regular laptop, iPhone, or otherWi-Fi enabled handheld device.
National Public Radio did a story last week on this:[The $100 Laptop Heads for Uganda]where they interview actor [Masi Oka], best known from the TV show ["Heroes"], who has agreed to be their spokesman.At the risk of sounding like their other spokesman, I thought I would cover the technology itself, inside the XO,and how this laptop represents IBM's concept of "Innovation that matters"!
The project was started by [Nicholas Negroponte] from [MIT University] as the "$100 laptop project". Once the final designwas worked out, it turns out it costs $188 US dollars to make, so they rounded it up to $200. This is stillan impressive price, and requires that hundreds of thousands of them be manufactured to justify ramping upthe assembly line.
Two of IBM's technology partners are behind this project. First is Advanced Micro Devices (AMD) that providesthe 433Mhz x86 processor, which is 75 percent slower than Thinkpad T60. Second is Red Hat,as this runs lean Fedora 6 version of Linux. Obviously, you couldn't have Microsoft Windows or Apple OS X, as both require significantly more resources.
The laptop is "child size", and would be considered in the [subnotebook] category. At 10" x 9" x 1.25", it is about the size of class textbook,can be carried easily in a child's backpack, or carried by itself with the integrated handle. When closed, it is sealedenough to be protected when carried in rain or dust storms. It weighs about 3.5 pounds, less than the 5.2 pounds of myThinkpad T60.
The XO is "green", not just in color, but also in energy consumption.This laptop can be powered by AC, or human power hand-crank, with workin place to get options for car-battery or solar power charging. Compared to the 20W normally consumed bytraditional laptops, the XO consumes 90 percent less, running at 2W or less. To accomplish this, there is no spinning disk inside. Instead, a 1GB FLASH drive holds 700MB of Linux, and gives you 300MB to hold your files. There isa slot for an MMC/SD flash card, and three USB 2.0 ports to connect to USB keys, printers or other remote I/O peripherals.
The XO flips around into three positions:
Standard laptop position has screen and keyboard. The water-tight keyboard comes in ten languages:International/English, Thai, Arabic, Spanish, Portuguese, West African, Urdu, Mongolian, Cyrillic, and Amharic.(I learned some Amharic, having lived five years with Ethiopians.)There does not appear be a VGA port, so don't be thinking this could be used as an alternative to project Powerpoint presentations onto a big screen.
Built-in 640x480 webcam, microphone and speakers allow the XO to be used as a communication device. Voice-over-IP (VOIP) client software, similar to Skype or [IBM Lotus Sametime], is pre-installed for this purpose.
The basic built-in communication are 802.1g (54Mbs) that you can use to surf the web usingthe Wi-Fi at your local Starbucks; and 802.1s which forms a "mesh network" with other XO laptops, and can surf theweb finding the one laptop nearby that is connected to the internet to share bandwidth. This eliminates the need to build a separate Wi-Fi hub at the school. There are USB-to-Ethernet and USB-to-Cellular converters, so that might be an alternative option.
Flipped vertically, the device can be read like a book.The screen can be changed between full-color and black-white, 200 dpi, with decent 1200x900 pixel resolution. The full-color is back-lit, and can be read in low-lighting. The black-white is not back-lit, consumes much less power, andcan be read in bright sunlight. In that regards, it is comparable to other [e-book devices], like a Cybook or Sony Reader.
Software includes a web-browser, document reader, word processor and RSS feed reader to read blogs.The OLPC identifies all of the software, libraries and interfaces they use, so that anyone that wants to developchildren software for this platform can do so.
- Game mode
With the keyboard flipped back, the 6" x 4.5" screen has directional controls and X/Y/A/B buttons to run games. This would make it comparable to a Nintendo DS or Playstation Portable (PSP). Again, the choice between back-lit color,or sunlight black-white screen modes apply. Some games are pre-installed.
So for $399, you could buy a Wi-Fi enabled[16GB iPod Touch
] for yourself, which does much the same thing, or you can make a difference in the world.I made my donation this morning, and suggest you--my dear readers in the US, Canada and Mexico--consider doing the same.Go to [www.laptopgiving.org
] for details.