Continuing this week's theme on Storage Area Networks, today I thought I would talkabout the various terms we use for our equipment.
One area of confusion are the adjectives "entry-level", "midrange" and "enterprise-class".What do these mean? Well, as in the case of disk and tape, these three are all relative terms that are a combination of "small, medium, large" as well as "good, better, best".
- Entry-level switches are typically only a maximum of 8-16 ports.Ports can connect the switch to a server, a storage device, or another switch.These are sometimes called "edge" switches, as they might be found in the mostremote sections of an office campus, remote branches, or other isolated areasoutside the primary data center.
- Midrange switches typically have a maximum of 32-64 ports.More ports on a single switch means fewer switches (and fewer cables) to manage.
- These are called "directors" to distinguish them from entry-level and midrange offerings.Directors have a maximum of 140-528 ports, and because so many devices or switches can beconnected to them, they need to be extremely reliable. Directors are designed for 24x7operation, with the ability to make most upgrades and configuration changes while the boxis running (often referred to as "non-disruptive upgrades"). Availability is typically better than "five nines", or 99.999 percent, which means that the box will be up 99.999 percent of the time, or conversely, will be down lessthan 5 minutes per year.
If you are asking yourself "which size is right for my company?" or "is my company big enoughfor a director?" you are asking the wrong questions! Instead, determine a SAN configurationthat meets your workload, and then decide the components for that design.
McData coined a phrase called "core/edge" design that is considered today as "Best Practice" throughout the industry.A good write-up can be found here at SearchStorage.com. Basically, you put your big beefy "core" directors in the center of the room, and then surround it with midrange switches, that then these connect to "edge" switches, that then connect to the servers and storage near them. As you grow, this design can easilyscale to grow with you.
So, if you need help implementing a SAN for the first time, or upgrading the one you have,call IBM, we can help!
technorati tags: IBM, SAN, switches, directors, entry-level, midrange, enterprise, non-disruptive, McData
Last week, Paul Weinberg of eChannelLine.com asks Is this the year of the SAN (again)?
So, I thought this week I would cover my thoughts and opinions on storage networking. We oftenfocus on servers or storage devices, and forget that the network in between is an entire worldon itself.
I believe Mr. Weinberg is basing this on the idea that in 2007, over 50 percent of disk will beattached over SAN, edging out the alternative: Direct Attached Storage (DAS). But perhaps 50 percentis the wrong number to focus on. In 2007, The United Nations estimates thatcities will surpass rural areas, with just over 50 percent of theworld's population. Does that make this the "Year of the City"? Of course not.
Instead, I prefer to use the methodology that Malcolm Gladwell uses in his book, The Tipping Point.(I have read this book and highly recommend it!)Gladwell indicates that the tipping point happens at the start of the epidemic, not when it is half over.Isn't it better to celebrate the sweet 16 debutante ball when young ladies have completed their years of training and preparation, and are ready to be introduced to the rest of the world, rather than after they are thirty-something, married with children.
Let's explore some of the history. Stuart Kendric has a nice 7-page summary on theHistory & Plumbing of SANs.
IBM announced the first SAN technology calledEnterprise Systems Connection (ESCON) way back in September 1990. This allowed multiplemainframe servers to connect to multiple storage systems over equipment called "ESCON Directors" that directedtraffic from point A to point B. Before this, mainframes sent "ChannelCommand Words" or CCWs, across parallel "bus and tag" copper cables. ESCON was serial overfiber optic wiring. SANs solved two problems: first, it reduced the "rat's nest" of cables between many serversand many storage systems, and second, it extended the distance between server and storage device.
For distributed systems running UNIX or Windows, the CCW-equivalent over parallel cables was called Small ComputerSystem Interface (SCSI). The SCSI command had over 1000 command words, so for its Advanced Technology (AT) personal computers (PC AT), IBM introduced a subset of SCSI commands called ATA (Advanced Technology Attachment). ATA drives supportedfewer commands, ran at slower speeds, and were manufactured with a less rigorous process. Today ATA drives are about 55 percent the cost per MB as comparable SCSI drives.
Anyone who has ever opened their PC and found flat ribbon cable with eight or sixteen wires in parallel, can understand that the same issues applied externally. Parallel technologies arelimited to distance and speed, as all the bits have to arrive at the end of the wire at approximately thesame time. Direct attach schemes with every server attaches directly to every storage device were also problematic.Imagine 100 servers connected to 100 storage devices, that would be 10,000 wires!
So, a new technology standard was developed, called Fibre Channel, ratified in 1994.The spelling of "Fibre" was intentionally made different than "Fiber" on purpose. "Fibre" is a protocol thatcan travel over copper or glass wires. "Fiber" represents the glass wiring itself.
Fibre Channel is amazingly versatile. For today's Linux, UNIX and Windows servers, it can carry SCSI commands, and the combination of SCSI over FC is called Fibre Channel Protocol (FCP). For the mainframe servers, it can carry CCW commands. Running CCW over Fibre Channel is called FICON. This convergence allows mainframes and distributed systems to share a common Fibre Channel network, using the same set of switches and directors.
We saw the use of SANs explode in the marketplace over the past 10 years, and then cool down with a series of mergers and acquisitions. Last year, Brocade announced it was acquiring rival McData, so we will be down to two major players, Cisco and Brocade.
So, IMHO, I think we are well past the "Year of the SAN".
technorati tags: IBM, SAN, storage, disk, United Nations, population, tipping point, Malcolm Gladwell, ESCON, SCSI, FCP, FICON, ATA, Brocade, McData, Cisco, Linux, UNIX, Windows
Continuing this week's theme of New Year's Resolutions for the data center, today we'll talk about one that people don't always think about on a personal level, that is to hone your tools and skills.
A long time ago, I used to be a regular speaker at the SHARE user group conference. One of the most attended sessions was Sam Golob presenting the latest CBT Tape set of tools. Over time, this large collection of "mainframe shareware" was handed out on 3480 tape cartridges, then on CDs, and finally made downloadable off the web.Sam's main point, which I remember to this day, was that everyone who has a job should figure out what tools they use, keep those tools functioning properly, and learn to use them well.
Later, I took some cooking classes at a culinary school. Among other things, we learned:
- A sharp knife is safer and easier to use than a dull one, resulting in fewer accidents
- Knowing what you are doing is the difference between food that is "simply awful" to that which is "awfully simple" to prepare.
- A well trained chef can prepare most meals with just a sharp knife and wooden spoon.
This last point hits close to home, as many people like me have too many tools that they do not use often enough to know how to use them well. Do I really need my strawberry corer, garlic press, or a tray designed for the storage and delivery of deviled eggs?
The same could be said about software tools. What tools do you use in your job? Do you feel you know how to take full advantage of their power and capabilities?If you develop software, do you know all the features for your debugging tools? If you develop advertising or marketing materials, do you know all the features of your photo or video editing software? If you manage storage in a data center, do you know all the tools for managing your storage area network (SAN), disk systems, tape libraries, and reporting tools to identify all of your files and databases across your entire IT environment?I would not be surprised if you could replace a whole mess of tools with just one, such as the IBM TotalStorage Productivity Center.
For me, I resolve to learn how to better use Lotus Notes e-mail client, and perhaps the new Office 2007.
technorati tags: Sam Golub, SHARE, CBT, tape, disk, SAN, mainframe, cooking, tools, IBM, TotalStorage Productivity Center, Lotus Notes, Office 2007
Happy New Year!
This year I resolve to be more consistent in my blogging, and my goal is to give you one to five entries per week, every week, based on the advice from Glenn Wolsey, Jennette Banks, and others.On some weeks, I will have a running theme, so rather than super-long entries to cover everything I can think of on a topic, make the entries short and readable. This week is a good time to review last year's "New Year's Resolutions" and to make new ones for 2007. I will discuss actions that companies can adopt for their data centers.
A common resolution is to lose weight, as in this Dilbert comic. Last year, I resolved to lose weight in 2006, and am delighted with myself that I lost eight pounds. When people ask for the secret of my success, I whisper in their ear "Eat less, exercise more." In general, people (and companies) know what to do, but just don't do it, which Pfeffer and Sutton document in their book The Knowing-Doing Gap. In my case, it involved lifestyle change: I exercised at a gym three times per week in Tucson, with a personal trainer, and revamped my diet.
Not everyone subscribes to the "eat less exercise more" philosophy. For example, Ric Watson argues in his blog that you can eat fewer calories, but eat more in actual volume, by choosing the right foods. This brings up the issues of "metrics" that most data centers are familiar with. Last year, I read the book "You: On a Diet" which explains that it is better to focus on "waist reduction" as measured in inches around your mid-section at the belly button, than "weight reduction" as measured in pounds. This year, I resolve to get down to 35 inches by the end of 2007.
The problem with measuring "weight" is that you are weighing bones, muscle and fat. A person can gain ten pounds of muscle, lose ten pounds of fat, and the scale would indicate no progress. The same problem occurs in data centers. How many TB of data do you have? Storage admins can easily tell you, but can they tell how much of this is bone (data needed for operating infrastructure), muscle (data used in daily operations that generates revenue) or fat (obsolete or orphaned data)?
We at IBM often state that "Information Lifecycle Management (ILM)" is more lifestyle change than a "fad diet". Figuring out what data you should capture in the first place, where to place it, when to move it, and when to get rid of it, is more important that just buying different tiers of storage hardware. So, for those looking to make new data center resolutions, I suggest the following actions:
- Re-evaluate the metrics you now use, and determine if they are helpful in making decisions and taking action.
- Come up with new ones that are more focused to solve the issues you face.
- Consider storage infrastructure software, such as IBM TotalStorage Productivity Center, to help you gather the information about your SAN, disk and tape systems, calculate the metrics, and automate the appropriate actions.
If you don't know where to start with ILM, certainly IBM can point you to the right solutions,best practices, techniques, and whitepaper.
technorati tags: Glenn Wosley, Jennette Banks, New Years resolutions, weight reduction, Diet, ILM, Information Lifecycle Management, IBM, TotalStorage Productivity Center
For those of us in the northern hemisphere, yesterday was this year's Winter Solstice
, representingthe shortest amount of daylight between sunrise and sunset. So today, I thought I would blog on my thoughtsof managing scarcity.
Earlier in my career, I had the pleasure to serve as "administrative assistant" to Nora Denzel for the week at a storage conference. My job was to make her look good at the conference, which if you know Nora, doesn't take much. Later, she left IBM to work at HP, and I gotto hear her speak at a conference, and the one thing that I remember most was her statement that thewhole point of "management" was to manage scarcity, as in not enough money in the budget,not enough people to implement change, or not enough resources to accomplish a task.(Nora, I have no idea where you are today, so if you are reading this, send me a note).
Of course, the flip-side to this is that resources that are in abundance are generallytaken for granted. Priorities are focused on what is most scarce. Let's examine some of theresources involved in an IT storage environment:
- Capacity - while everyone complains that they are "running out of space", the truth is that most external disk attached to Linux, UNIX, or Windows systems contain only 20-40% data. Many years ago, I visitedan insurance company to talk about a new product called IBM Tivoli Storage Manager. This company had 7TB of disk on their mainframe,and another 7TB of disk scattered on various UNIX and Windows machines. In the room were TWO storage admins for
the mainframe, and 45 storage admins for the distributed systems. My first question was "why so many people forthe mainframe, certainly one of you could manage all of it yourself, perhaps on Wednesday afternoons?" Their response was that they acted as eachother's backup, in case one goes on vacation for two weeks. My follow-up question to the rest of the audience was:"When was the last time you took two weeks vacation?" Mainframes fill their disk and tape storage comfortablyat over 80-90% full of data, primarily because they have a more mature, robust set of management software, likeDFSMS.
- Labor - by this I mean skilled labor able to manage storage for a corporation. Some companies I have visitedkeep their new-hires off production systems for the first two years, working only on test or development systemsonly until then. Of course, labor is more expensive in some countries than others. Last year, I was doing a whiteboard session on-site for a client in China, and the last dry-erase pen ran out of ink. I asked for another pen, and they instead sent someone to go re-fill it. I asked wouldn't it be cheaper just to buy another pen, and they said "No, labor is cheap, but ink is expensive." Despite this, China does complain that there is a shortage of askilled IT labor force, so if you are looking for a job, start learning Mandarin.
- Power and Cooling - Most data centers are located on raised floors, with large trunks of electrical power and hugeair conditioning systems to deal with all the heat generated from each machine. I have visited the data centers ofclients that are forced now to make decisions on storage based on power and cooling consumption, because the coststo upgrade their aging buildings are too high. Leading the charge is IBM, with technology advancements in chips, cards, and complete systems that use less power, and generate less heat. While energy is still fairly cheap in the grand scheme of things, fears ofGlobal Warmingand declining oil supplies, the costs ofpower and cooling have gotten some news lately. In 1956, Hubbert predicted US would reach peak oil supplies by1965-1970 (it happened in 1971), and this year Simmonsestimated that world-wide oil production began its decline already in 2005. Smart companies like Google have movedtheir server farms to places like Oregon in the Pacific Northwest for cheaper hydroelectric power.
- Bandwidth - Last year IBM introduced 4Gbps Fibre Channel and FICON SAN networking gear, along with the servers and storage needed to complete the solution. 4Gbps equates to about 400 MB/sec in data throughput. By comparison, iSCSI is typically run on 1Gbps Ethernet, but has so much overheads that you only get abour 80 MB/sec. Next year, we may see both 8 Gbps SAN, and 10 GbE iSCSI, to provide 800 MB/sec throughputs. My experience is that the SAN is not the bottleneck, instead people run out of bandwidth at the server or storage end first. They may not have a million dollars to buy the fastest IBM System p5 servers, or may not have enough host adapters at the storage system end.
- Floorspace - I end with floorspace because it reminds me that many "shortages" are temporary or artificially created. Floorspace is only in short supply because you don't want to knock down a wall, or build a new building, to handle your additional storage requirements.In 1997, Tihamer Toth-Fejel wrote an article for the National Space Society newsletter that estimated that ...Everybody on Earth could live comfortably in the USA on only 15% of our land area, with a population density between that of Chicago and San Francisco. Using agricultural yields attained widely now, the rest of the U.S. would be sufficient to grow enough food for everyone. The rest of the planet, 93.7% of it, would be completely empty.Of course, back in 1997 the world population was only 5.9 billion, and this year it is over 6.5 billion.
This last point brings me back to the concept of food, and I am not talking about doughnuts in the conference room, or pizza while making year-end storage upgrades. I'm talking aboutthe food you work so hard to provide for yourself and your family. The folks at Oxfam came up with a simpleanalogy. If 20 people sit down at your table, representing the world’s population:
- 3 would be served a gourmet, multi-course meal, while sitting at decorated table and a cushioned chair.
- 5 would eat rice and beans with a fork and sit on a simple cushion
- 12 would wait in line to receive a small portion of rice that they would eat with their hands while sitting on the floor.
So for those of you planning a special meal next Monday, be thankful you are one of the lucky three, and hopefulthat IBM will continue to lead the IT industry to help out the other seventeen.
Happy Winter Solstice!
technorati tags: IBM, Northern, Hemisphere, Winter, Solstice, Nora+Denzel, Oxfam, scarcity, Linux, UNIX, Windows, TSM, Tivoli+Storage+Manager, storage, admins, global+warming, climate+change, peak+oil, National+Space+Society, special, meal