Hot-Swappable OS Anyone?
Posted by Zerin
So, just a couple minutes ago I was feeling reckless. I was going to unplug my single hard drive from my work machine. It’s just the SATA drive that contains the running OS. SATA is the newer hard drive interface that is Hot-Swappable. This reminded me of a time when IDE was as delicate as a Stone Butterfly. One of my coworkers runs XP on his system and when his poor machine hit the floor, the system worked for a while before blue-screening, when he checked it, his system drive loosened and disconnected, explaining the BSOD. One reboot later, all was well.
But how does a modern system like say Fedora 16 or Windows 7 handle these issues? (I happened to be running Fedora 16 on my system.) I wondered, what would happen if I pull out my main hard drive while my computer is still running?
Well I’ll be to the point, it still works, somewhat, it doesn’t blow up let’s just leave it at that. The mouse moved, I could move through the menus, though some icons where missing. I could look though my documents, though they where all locked and empty, maybe cause the hard drive was missing, and when i looked through the file manager, the hard drive was not there. I could not launch any program, since it would bring up something like, could not launch process, file missing, bla bla bla. But I could still use my remote desktop program like usual. So after 5 minutes everything seemed normal. WHY?
Not that I appreciate that it didn’t crash, but the first thought that came to my mind was, it’s all running in the RAM. If you remember our last lesson about RAM, it stands for Random Access Memory, This means that anything that your computer is doing is being stored in here until it gets tired of holding it for you and drops in the the hard drive. So if you are running a game, chances are that most of that game is being held in the RAM. If you are looking at pictures, they are in the RAM. This seems like the most logical solution and i’m willing to be it’s the right answer.
So why did XP fail. ONE, it’s an older system that was meant to run on IDE drives that where not hot swappable and uses little RAM. Wait? Isn’t using little RAM a good thing? For speed, yes. But in this case, since it was not holding most of the important system files in the RAM, when it tried to access something, it caused a major failure. Bummer.
So newer OS’s should be able to handle this situation. Let’s go back to my machine, I plugged in the hard drive and it recognized it! But the issue came when I tried to mount it. See my hard drive was encrypted. So in order to access my data, it needed to load up the encryption program so when I put in my password, it could verify, unfortunately that program was not in the RAM, but in the hard drive, encrypted. Oh well, quick reboot it worked fine again, no disk check, no nothing.
In the end, my theory goes that if your hard drive is not encrypted and you do the same thing, I assume that when you plug it back in, everything should be fine. This of course depends heavily on what OS you are running, what encryption, if any you are using, and what you are doing at the time the drive is being pulled out.
I want to try this on a Windows 7 Machine, but no one wants to let me borrow one here, they think I might break it or something, scaredy cats.
OK, it was only seconds ago I got my hands on a Win 7 machine and this System had a Pantherpoint PCH, IVB processor, and before I start, I do want to say that this system is an unfinished production testing unit. I do not know yet how a real world system will react. We shall proceed.
OK so first things first, I booted to Windows 7, let the system run for 10 minutes, then pulled out the hard drive, I had one program running, but once I clicked on the start menu, nothing, I tried my computer, nothing, opening a folder nothing, then IO(input output) errors and explorer crashed, I could maximize and minimize the program window, but slowly by slowly everything started closing and panicking. Services stopped, everything was gone except for the background and pointer that stilled moved. CTRL ALT DELETE worked but that’s it. This all happened under a minute. When I replugged the hard drive, BSOD then reboot. All is fine now.
WHY? Talking to my coworkers (Windows fanboys) here explain: Windows uses a lot more resources than tiny Linux. True, my whole Fedora 16 with Remote Desktop, Wine and Skyrim on it, takes only 18Gigs. Full Windows barebone take up that space, my ram usage is 600MB My install CD was 700MB! Windows 7 takes up 546 MB but still, most of it’s system files are on the drive, not in the RAM.
Also another good explanation for why this happens. Hot-swappable….. SATA hard drives, yes, Windows’s no. One of my coworkers said, “OS’s are not hot swappable” I wanted to argue, but whatever, Fedora Linux is :) Why is this important, why should you care? Because, like it happened to my coworker, if you tip over your machine, the hard drive falls out. Wouldn’t you want to plug it back in and keep on working?
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Posted on November 14, 2011, in Computers and Internet and tagged Fedora, Microsoft Windows, Operating system, Random Access Memory, SATA, Serial ATA, Windows, Windows 7. Bookmark the permalink. Leave a comment.