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  1. #1
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    USB drive isolation

    My daughter's power supply died in a flash taking the video card, and both system HDD and backup HDD with it. All her nice image backups are gone. Is a USB external drive isolated enough that it would probably survive such a disaster or should I have done backups to separate computer or the cloud ?

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    Super Moderator BATcher's Avatar
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    The logical answer to this one is, "Why don't you try it out?"
    Any other answer is pure speculation.
    BATcher

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    Super Moderator RetiredGeek's Avatar
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    A USB drive will be isolated enough if, and only if, you unplug it from the computer when you are not using it! HTH
    May the Forces of good computing be with you!

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    I second RG's response. In addition, unplug the external drive's power supply, so it won't get fried if your house is hit by lightning.

    Consider backups to the cloud (in addition to the local external drive) as a secondary, not primary, solution.

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    Super Moderator CLiNT's Avatar
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    Quote Originally Posted by cranerw3156 View Post
    My daughter's power supply died in a flash taking the video card, and both system HDD and backup HDD with it. All her nice image backups are gone. Is a USB external drive isolated enough that it would probably survive such a disaster or should I have done backups to separate computer or the cloud ?
    As RG states, at least one of your main backups drives should be external, kept separate, and only used when modifying and backing up.
    Which means that it should remain disconnected when not in use for the above purposes.
    DRIVE IMAGING
    Invest a little time and energy in a well thought out BACKUP regimen and you will have minimal down time, and headache.

    Windows 8.1, 64 bit
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    Thank all of you for your responses. I should have been able to figure that out myself but I am slowing down for some reason (82 years old now). To Batcher, I am not sure I want to risk a functioning USB drive to test it. The logic of unplugging the USB drive except when actually using it makes sense but would be at risk to my degree of attention. The combination of USB external drive and cloud is certainly best. I, myself use a network connected server for backups but it is at risk to whole house surges like lightening, so I will now arainge cloud backups for irreplaceable data.
    RWC

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    Super Moderator CLiNT's Avatar
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    You could solve the problem by getting two drives, but only keeping one connected regularly.
    The other, you would just have to remember to keep current, but separate.

    The chances of a power supply taking out your external drives are pretty remote at any rate.
    DRIVE IMAGING
    Invest a little time and energy in a well thought out BACKUP regimen and you will have minimal down time, and headache.

    Windows 8.1, 64 bit
    Motherboard: DX58SO2*Chipset: X58 Express/Intel ICH10*BIOS: SOX5820J.86A.0888.2012.0129.2203*Processor: Intel Core i7 CPU X 990
    GPU: Nvidia GTX 580*Memory: Corsair 12 GB, 4x3@1600*PSU: Corsair HX1000*Hard drives: REVO X2 160GB*OCZ VERT X3 120GB*5 mechanical storage drives (12 TB) total.

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    I once experienced a failure where I assumed exactly what you state. Further investigation revealed that it was the reverse that caused the failure. In my case it was the video card that took out the other components, (perhaps???), ???. Hmmm, yet even further investigation revealed that the HDD was not destroyed at all. It was very recoverable. In order to find the HDD drive was still good, I removed it from the destroyed computer and placed it in a portable USB enclosure which allowed it to connect to a USB port. The OS was not functioning this way, but all else was available and recoverable.
    Just saying, perhaps???
    Michael

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    Other things to consider

    Hi All:

    I'm surprised no one also mentioned that you should always use a known good surge protector. If you had one before, its probably blown, too, so replace it with a heavy duty model. At the risk of some additional cost, you might also want to consider adding a UPS (uninterruptible power supply) of sufficient size to allow not just some additional surge protection, but also the ability to run for some period of time during loss of utility power. I have a 750kWA (overkill size!) on my system(s), which is enough to run both my desktop PCs, KVM switch, LCD monitor, DSL modem to keep connected to the web, and my two Vonage boxes for VOIP phones, for about 15-minutes -- enough time for graceful shutdown. There are protected and non-protected outlets on it. If you have an inkjet printer that would work on it, too, but NOT a laser printer (too much "juice" needed). We don't get much lightning in my area (SF East Bay), but occasionally it happens. We do lose power in my neighborhood way too often. It is so cool to have all the lights in the room go out, but the PC never even flickers... Last time that I had to replace my garage door opener, I even got one with a UPS that lasts for up to a dozen up-down cycles.

    As far as backups, I use more than one internal removable rack drives, 2 TB, which have more than enough space for native file (copy) of all my data, plus image backups of the attached PC plus several other systems. I swap them out regularly and back up the backup to another separate 2 TB removable drive on a different PC that is rarely turned on, so I feel pretty safe.

    Works for me. Hope that provides some food for thought. Best wishes.

    Rob
    Last edited by rbsteinbach; 2014-01-09 at 10:28.

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    maybe

    try it !!

    get a surge suppressor and a ups with surge suppression
    use both in series

    best to have two HD usb drives that you alternate
    only plug one in at a time

    also stops virus from contaminating both at once

  13. #11
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    get a surge suppressor and a ups with surge suppression
    use both in series
    IIRC, there's some reason for NOT running them in series, but I can't remember why (even if I did know at one time).

    Zig

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    Super Moderator RetiredGeek's Avatar
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    Zig, All,

    You should never plug a UPS into a surge suppressor (wall - UPS - Surge). However, it is ok to plug a surge suppressor into a UPS. (wall-UPS-Surge) At least that is my understanding of the situation and currently how I have mine setup. HTH
    May the Forces of good computing be with you!

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  15. #13
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    RG,

    I believe your first example should be (wall - surge - UPS).

    Zig

  16. #14
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    Sometimes, the USB device with power adapter (or wall wart) could fry the laptop/PC, rather than the other way around.
    It happens more frequently than the reverse.
    USB device with its own power adapter could be quite damaging to the rest of the system, especially if a laptop is powered off.
    Use a USB hub in the middle.
    The hub helps to isolate. And if something happens, the hub burns first as sacrificial lamb.
    Technical reason:
    USB cable includes 5V and ground wires. The other pair is data wires. The 5V wire could be directly connected to the PC's 5V line. That is, the 5V on USB device is connected to the 5V of your PC power supply! Some USB devices have mechanism or IC/fuse to do the separation. Some *DON'T*. (You don't know unless you open and study it. Brand name has some guarantee but not always.)

    I propose make it a habit to only plug into a hub than directly to a laptop/PC.

    Laptop, with less muscular power supply, is more vulnerable. Even Apple laptops.
    Hint: if the laptop/PC cannot boot normally, unplug all USB devices, especially those with its own wall wart or power supply. Then thank God your PC/laptop is not burned.

    Re surge suppressor:
    Surge suppressor, basically, is a fast acting high voltage Zener Diode (aka Voltage limiter). (I skip the details here.)
    Say, at 400V, it caps. So a 1000V spike is limited to 400V. Damage is measured in energy. In turn, it is measured in time duration of the spike. Most spikes, though high voltage, is only nano-seconds long and quickly decay, hence 'low' energy. The 'voltage limiter' can handle it.
    The basic not so good characteristic of surge suppressor is its high capacitance. The capacitance may short out high radio frequencies in the AC line.
    Depending on application, it could be good (suppressing noise). For Ethernet over Powerline, or radio frequency control using AC line, it is a nightmare, no less.

    With this understanding, plug anything before, after, in between, suppressor(s), should have no consequence. (Unless of course, your PC, or your UPS, is constantly outputting 400V or higher AC voltage!)

    As for surge suppressor in series:
    Someone already mentions: No good. Worse, actually... but not as bad.
    Tech:
    As mentioned, suppressor device is to create a short between 2 wires.
    The nano-second spike could create as much as 10 Amps or higher.
    Worse still, at nano-second rise time, it is effectively very high frequencies.
    Skin effect is in full force. All this high current only rides on surface area of the wire, making the wire a lot more resistant.
    Bad enough? Now that is not as bad as this: Wire inductance.

    All wire, even an inch long straight wire, has inductance. At very high frequency, its inductance is high enough to almost block the high frequency current.
    Now imagine a 6-foot power strip connected to another 6-foot power strip. When the 2nd power strip suppressor limits, the current now has to pass through its own 6-foot 'inductor', then to ANOTHER 6-foot 'inductor'. Effectively, the wires 'float' way above ground level. Or, bad protection.
    The most effective suppressor protection is a wall plug, directly plug into the wall outlet, not a power strip with 3 or 6 feet tail. That is, when the 'voltage limiter' shorts the two wires, it sees only the AC outlet terminals.

  17. #15
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    Quote Originally Posted by cranerw3156 View Post
    My daughter's power supply died in a flash taking the video card, and both system HDD and backup HDD with it.
    Nothing in these symptoms even suggest it was an external surge. These are classic symptoms of a power supply that was missing essential functions. These defective supplies are often sold to computer assemblers who have no electrical knowledge.

    A destructive voltage created by a supply that is missing essential functions would be incoming to every PC components - including USB connected devices.

    Those same functions also define protection inside the power supply that is superior to any power strip or UPS protection. Unfortunatey, too many recommend power supplies without citing the always important numbers and because they do not even know what numbers are important. That damage is classic of a computer's power supply that was defective when purchased.

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