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Month: November 2018

IT v Security

IT v Security

One of my best friends is an IT guy, with about the same amount of career experience as I have.  (We’re old, get it?)

When we get together, I notice that we each show the distinctive mindset of our specialties: he’s always thinking, How can I get this to work?  And I’m always thinking, How can I break this?

And yet, it was he who sent me this:

Don’t be put off by the length – the time will fly by
Uptime 3: Climate Change

Uptime 3: Climate Change

Data centers with thousands of computers in concentrated amounts of floor space do have to expend enormous amounts of energy keeping things cool.  Your home data center can almost entirely ignore this issue, except where your computers have to be enclosed.

Server Closet.  Or at least, a server IN A closet.

At some point, you will want some of your servers out of sight.  Any machine that provides some service via the network without being needed in front of you is a server.  Home aesthetics will at some point demand that the thing get out of sight.

Your computer’s case has one or more fans that circulate air through it for cooling.  The fan draws in room air, heats it some with heat generated by the components operating inside, and then ejects it back into the room.  A typical room is large enough to absorb this without moving the needle much on the overall room temperature, so the process can continue more or less indefinitely.

The problem you encounter when putting a computer into a closet is, soon after the door is closed the computer is drawing in and heating already rather-hot air, and the temperature in the closet starts rising.  Much over 95F/35C, and you’re going to start having components on your system board begin to behave erratically or fail.

So don’t let things in there get too hot.  Check if it’s heating up steadily in there, and open the door a bit if you have to.  If you can, add a vent at the bottom of the door, and an exhaust fan or two at the top.  If you get a couple of 180mm fans that are designed to be installed is computer cases, you can probably work out how to power them outside a case, and you will find that they are really, really quiet.

Note: however you route your network cables in and out of the closet, be sure the door is not pinching them every time it opens or closes.  Eventually, a conductor in there will break and you will get to 1) do a really “fun” troubleshooting session, then 2) shop for a new network cable. 

Another thing you will want to avoid during the heating season is letting the air get too dry.  If that happens, you will have a tendency to build up static electric charge on yourself as you move around.  You can potentially zap your computers when you touch them, damaging random expensive things inside them. 

If you can add humidity to your environment, do so.  Get the relative humidity to about 50%, give or take 10%.  But (and this is important!) do NOT use a misting humidifier, one that sprays droplets into the air to evaporate there.  Be sure to use a humidifier that evaporates the water inside it, so the vapor that comes out is pure water.  If your humidifier sends droplets of tap water into the air, when the water evaporates, it will let the salts and minerals dissolved in it float down to the surfaces in the room, forming a fine white dust that you will see everywhere.  This dust has the potential to short out connections on printed circuit boards, causing all kinds of very expensive havoc.

Also don’t let the wiring in your server closet get away from you.  Like this guy did.

There are worse than this.  See /r/cablegore

Uptime 2: The Power

Uptime 2: The Power

Your home is your data center.

Maybe this sounds like a stretch but, unless you live a very low-tech existence (like this guy, perhaps?), this is how we all live now in the 21st century.  Oh sure, you are not going to have to have raised floor to accommodate miles of wiring, or forty tons of lead-acid batteries for power leveling, or gigantic Liebert chillers for cooling down hundreds of servers.  Still, it would be a good idea to give some thought to how your environment can be more comfortable for the dozens of computing devices that make modern life tick.  We don’t necessarily have to keep our homes to the strict environmental standards of large data centers.  Still, it pays not to subject our computing devices to too much environmental stress. 

Consider power. If a device works from a battery, which you recharge when you can, then it will be less sensitive to fluctuations in the power that comes out of your wall sockets. But devices that work straight off your line power can be quite sensitive to spikes or sags. Even if they take the power through a transformer (“wall wart”) it probably offers little or no protection from spikes that can damage the equipment.

Batteries directly power the large data centers, while being continuously recharged from line power or generator 

You won’t have a large roomful of batteries through which to pass all your electricity, providing an absolute filter against voltage sags and spikes. But for any of your digital devices that run on AC power out of a wall plug, you need to consider how to condition the power they get.  Though there are many options, the ones I want you to consider are a good surge suppressor and a UPS. 

Surge suppressors are best for:

  • Devices that have some internal battery capacity, e.g. laptops
  • Devices that will not lose data if the power drops — at least, no data that you care about

Not all surge suppressors do much in the way of suppressing potentially damaging surges.  Some are no more than power strips with a marketing makeover.  I use sites like The Wirecutter to figure out which ones are worth my attention.

For devices that have much more severe consequences when the power drops, you should be looking at a UPS.  A UPS is a teeny-tiny version of that roomful of batteries you see above: the line power keeps a battery inside the UPS charged, and that battery is what actually sends power to your equipment.  Consider a UPS for:

  • Desktop computers
  • Servers
  • DVRs
  • Networking equipment – cable or DSL modems, firewalls, switches, WiFi access.

UPS’s are sized in “VA” which means volt-amps.  Think of a VA as a unit of current to be supplied.  The more VA you have, the longer power will last after a utility failure.  But the larger the device(s) being powered, the faster it draws down VA from the UPS, so the less time you get. You can use a larger UPS to get more time or to power more devices.  Remember, for a desktop computer, you’re going to want to power the display, and any attached external hard drives as well.

I typically use a UPS between 750-1000 VA for a desktop computer.  This gives me enough time to finish up what I am doing, or at least get to a decent stopping point before I run out of juice.  If I can shut down my computer on my own terms during a power outage, I count that a win.  But in case you are not home, be sure every desktop and server is using the critical feature of most UPS’s: to connect a data cable and run a small background app that gracefully shuts down the system when the UPS informs it that the batteries are almost drained.  Otherwise, all you will have done by hooking up the UPS is delayed the sudden power failure by a couple of hours.

Another trick I have enjoyed during a few thunder-stormy evenings is using a smaller UPS (maybe around 500-600 VA) to power all my network gear.  The network stuff is less demanding and so lasts longer.  The result is, after two hours with no power from the utility, my server and desktop are dark.  But my iPad and my phone are happily using the WiFi to fetch email, check social media and even watch a little Netflix if I want.  I can even use that UPS to recharge my mobile devices as needed.

Uptime

Uptime

Every one of us has a data center to care for.  Not everyone takes it as seriously as some do.

The mouseover text for this one reads:

The weird sense of duty really good sysadmins have can border on the sociopathic, but it’s nice to know that it stands between the forces of darkness and your cat blog’s servers.

Point being, what’s trivial to you or me is not so trivial to someone.  And if that someone is a member of your household then you need to take it seriously, if for no other reason than shalom bayit

Think about the things a data center does to create a fundamentally good environment for the computers it houses: climate control, power protection, redundancy, fire protection, physical security.  

But Kahomono, I hear you saying, my house is not a data center!  Oh no?  Let’s talk about a job I had a few years ago.  OK, quite a few years.  But still: we were opening a new data center for a major NYC bank.  We had three computer rooms: the Mainframe room had 8 IBM 390s.  The Time-Sharing room had 4 Honeywell DPS-8s.  And the Mini room had about a dozen computers of various makes: Data General, Pr1me, Tandem, Digital.  There were also a handful of IBM PCs floating around, with which nobody was very impressed.  So let’s round up and say that this “Data Center” — and it was surely that — had about 30 computers housed in it.

How many computers in your home now?  Do you even know?  I can say that in a typical home housing a family of four, you probably have… more than in my 1980’s era data center.  40?  Maybe close to 50?  Consider that your phones and tablets, your set-top boxes, DVRs, gaming consoles, “smart home” controllers and endpoints, not to mention every “smart” appliance you connected to your poor overtaxed WiFi, are all computers at least as powerful and capable as that VAX in our Mini room back in the day.  So if you only counted your desktops and laptop computers, you missed the mark by around 90%, is my guess.

And every one of those computers is capable of violating at least one tenet of information security.  (Remember CIA?) 

  • Confidentiality: it could leak information about you and your activities that you would rather it didn’t.  
  • Integrity: It could damage or alter information it holds, making it less useful or even harmful to you
  • Availability: you could lose information you don’t want to lose.  Think emails, tax returns, photos, music collections, movies, saved game progress.

So what do you do about it that doesn’t turn you into that guy in the cartoon above?  More on that to come.

this post originally appeared on Kahomono – It Means Lucky.