While teaching me to drive, mother once told me, "You can't see where you're going with the rear-view mirror; only what you've just run over." What my Mom was eloquently trying to tell me was, look forward while moving forward. These are erudite words for us in the IT world also….most of the time.
Many IT organizations find, at one time or another, they're in jeopardy of running out of space. Who's job was it to inform the decision makers of this rapidly approaching "brick wall" on our information super highway? Answer: everyone's.
Everyone these days is familiar with storage space forecasting. Doctors, nurses, executives, IT staffers, even my 10 year old. Do I hear some laughter from the audience? OK, quick test: How many gigs of memory does your smart phone, or iPad have? If you bought it, I'll bet you are pretty sure you know. The sad part of this is, I'll bet if I asked you, "How much space do you have left on that device?" that almost no one (myself included) would know. Why? We've become conditioned to "soft warnings" by the consumer electronics world that help us deal with running out of space. How many people reading this have, at one time or another, had to delete photos from either your digital camera, or smart-phone to make room for something you desperately needed? I certainly can't speak for you, but I have.
As my coworker Mark Luquire called out in his blog, "Is Monitoring Really Important", simple monitoring of storage consumption is something I see practiced less aggressively. All of the new storage devices provide super nifty tools that will alert administrators when they hit, "high water marks". This is only one tine of the fork we need to put into this process. Actively tracking and trending storage consumption is one of the most beneficial exercises you can undertake in your environment today.
How many times have you heard, "Storage is cheap", only to have someone cough up a lung at a budget meeting when someone says they need $50,000 for additional storage. Actively reporting storage consumption and providing trending analysis can greatly reduce the shock factor of these announcements. Knowing the tricks for how to do this effectively can greatly reduce the time required to keep on top of this.
Almost everyone has excel on their PC's these days. Lay out the servers that consume storage in a spreadsheet that makes sense to you. Here is my example:
In my example, server name and LUN size are the first two consistent columns. After that, put in the month you want to start tracking storage from. If you aren't using a management console that keeps track of free space, you'll need to manually examine each drive you want to track and record how much "space free" you have.
Another way I advise customers to start is to go to the backup server and look at the logs. This should show how much data was backed up, and when. In a MEDITECH environment that only works for Data Repository, so you may have to resort to some basic Windows PowerShell scripting. This isn't as scary as it sounds. Microsoft TechNet provides a "Hey, Scripting Guy!" blog. A quick Google search for "PowerShell script free disk space" came back with this link: http://blogs.technet.com/b/heyscriptingguy/archive/2012/08/08/use-powershell-to-create-a-report-displaying-free-disk-space.aspx . Once you have this data, put the oldest entry at the beginning so you have a linearly decremented list. Example: With this data, you can now create a chart. Go to a new Tab in Excel, click Insert and select Scatter Chart with only markers. You will now have this:
Leaving this box alone, click on the tab containing your data and select the range that contains the actual data you want: And then click OK. As in my example, you will now have this great little scatter chart that shows the storage points for FS-01 and FS-02 as such:
This will open a dialog box that will, about 3/4 of the way down, give you an option to select the number of "Forecast" periods you want. If you are tracking storage consumption by month, this would be months as in my example. I enter "36" to trend how much storage I'll consume, given my historical rates, over the next 3 years:
Do the same for FS-02 and you will end up with a nice little executive-friendly chart that clearly shows when you will run out of storage:
The most difficult part of this exercise is the initial setup. Once you have the sheet and mechanisms to discover current free space, you'll be able to update your forecasts in a few minutes for all the world to see. This can even turn into a report that is reviewed at executive committee meetings, so when you go to management to say “I need $50,000 for more storage”, you’ll be able to add, “sometime in the next 24 months”. Here’s one example where my Mom was wrong. I CAN tell where I'm going by looking backward - and so can everyone else in my organization!
Just promise me you won't tell my Mom.
Clay Sides is a Senior Technical Consultant with Park Place International who specializes in helping customers hone in on their true objectives to ensure the biggest return on their investment. Clay gets satisfaction from working with customers to discuss their needs and provide consulting services that best address those needs. Identifying performance bottlenecks, assisting with building and implementing strategic plans for growth and sustainability, as well as recoverability, are all his specialties. Clay has been working in Information Systems since 1989, having spent time with United Technologies, Texas Instruments, Acer America, Palm Computing, Gateway and most recently, 5 years with JJWild/Perot/Dell. When asked, Clay says his favorite part of his current endeavor, is seeing the moment of realization in a customers' eyes when he's able to communicate a complicated plan, or concept, in terms they understand; "It's a rush when you actually see you've been able to help someone understand something. Their stress seems to almost float away at the moment of realization."