Re: SATA and Hot Swap (More info)

Discussion in 'Gigabyte' started by CSquared, Jan 2, 2009.

  1. CSquared

    CSquared Guest

    I found this discussion very interesting as I am wanting to be able to
    hot swap some drives myself. What is the symptom when one swaps a drive
    in or out that is not "hot swap capable"? Is the drive merely not
    recognized, or can hardware damage occur?
    Thanks,
    --
    Charlie C.
    To email me, eradicate obfuscate & remove dot invalid
     
    CSquared, Jan 2, 2009
    #1
    1. Advertising

  2. CSquared

    Paul Guest

    CSquared wrote:
    > I found this discussion very interesting as I am wanting to be able to
    > hot swap some drives myself. What is the symptom when one swaps a drive
    > in or out that is not "hot swap capable"? Is the drive merely not
    > recognized, or can hardware damage occur?
    > Thanks,
    > --
    > Charlie C.
    > To email me, eradicate obfuscate & remove dot invalid
    >


    It sounds like Carl has done more experiments with this
    than I have.

    If the hot swap is not working, then you wouldn't expect
    the system to see the disk at all. The event from the
    hardware, would not be raised to the software (because
    either the path is missing inside the driver code, or
    the OS itself doesn't support drives appearing out of
    nowhere).

    The SATA connectors are designed with hot swap in mind,
    and even if the driver code was missing, there should be
    no damage to the drive. If you look at the SATA cable,
    certain pins are longer than the other pins. Those pins
    touch first, and prevent negative voltages appearing on
    the sensitive data pins.

    If you look at the instructions for one of those
    SATA to USB converters, they suggest a certain order
    if connecting cables to a cold drive. Connect the 15 pin
    SATA power wafer first. Then connect the data cable second.
    When you think about it, you should be connecting your
    cables, to minimize vibration to a running drive, so one
    end of the data cable can be fastened to the drive first,
    then the power cable gets connected, and then the other
    end of the data cable goes to the motherboard.

    When you're finished with the drive later, and you want
    the OS to keep running, first you use the "Safely remove"
    icon in the tray, to flush the cache on the drive. Then,
    you'd unplug the data cable from the motherboard connector.
    (That way, there is no mechanical shock to the still-powered
    drive.) Next, disconnect the power to the drive, preferably
    by disconnecting an adapter cable from the power supply - not
    by yanking on a connector right on the drive. So when you're
    finished, you have a drive in your hands, with a power and
    a data cable still in place, but the other ends have been
    disconnected in a particular order. Once the drive spins
    down (give it 30 seconds or more), it is more resistance
    to shock, so you can carefully remove the cables from the
    drive.

    It is sorta like car batteries, when you give you buddy's car
    a boost. There is a certain order to connect the cables
    there as well, for safety reasons.

    HTH,
    Paul
     
    Paul, Jan 2, 2009
    #2
    1. Advertising

  3. CSquared

    CSquared Guest

    "Paul" <> wrote in message
    news:gjm2aa$7gl$...
    > CSquared wrote:
    > > I found this discussion very interesting as I am wanting to be able

    to
    > > hot swap some drives myself. What is the symptom when one swaps a

    drive
    > > in or out that is not "hot swap capable"? Is the drive merely not
    > > recognized, or can hardware damage occur?
    > > Thanks,
    > > --
    > > Charlie C.
    > > To email me, eradicate obfuscate & remove dot invalid
    > >

    >
    > It sounds like Carl has done more experiments with this
    > than I have.
    >
    > If the hot swap is not working, then you wouldn't expect
    > the system to see the disk at all. The event from the
    > hardware, would not be raised to the software (because
    > either the path is missing inside the driver code, or
    > the OS itself doesn't support drives appearing out of
    > nowhere).
    >
    > The SATA connectors are designed with hot swap in mind,
    > and even if the driver code was missing, there should be
    > no damage to the drive. If you look at the SATA cable,
    > certain pins are longer than the other pins. Those pins
    > touch first, and prevent negative voltages appearing on
    > the sensitive data pins.


    Both of the above paragraphs are pretty much what I would have expected.
    I really had not done my homework on this issue and probably should not
    have posted regarding it at all yet, but I figured what the heck - it
    was the first work day of the new year. :) Also, it is a subject in
    which I have more than passing interest.

    >
    > If you look at the instructions for one of those
    > SATA to USB converters, they suggest a certain order
    > if connecting cables to a cold drive. Connect the 15 pin
    > SATA power wafer first. Then connect the data cable second.
    > When you think about it, you should be connecting your
    > cables, to minimize vibration to a running drive, so one
    > end of the data cable can be fastened to the drive first,
    > then the power cable gets connected, and then the other
    > end of the data cable goes to the motherboard.
    >
    > When you're finished with the drive later, and you want
    > the OS to keep running, first you use the "Safely remove"
    > icon in the tray, to flush the cache on the drive. Then,
    > you'd unplug the data cable from the motherboard connector.
    > (That way, there is no mechanical shock to the still-powered
    > drive.) Next, disconnect the power to the drive, preferably
    > by disconnecting an adapter cable from the power supply - not
    > by yanking on a connector right on the drive. So when you're
    > finished, you have a drive in your hands, with a power and
    > a data cable still in place, but the other ends have been
    > disconnected in a particular order. Once the drive spins
    > down (give it 30 seconds or more), it is more resistance
    > to shock, so you can carefully remove the cables from the
    > drive.
    >
    > It is sorta like car batteries, when you give you buddy's car
    > a boost. There is a certain order to connect the cables
    > there as well, for safety reasons.


    That makes perfect sense to me. My current vision for using a removable
    drive is primarily as a mostly-non-spinning alternate backup for .jpg
    files I've saved from my camera. (I'm a firm believer in multiple -
    like 3 or more - backups for irreplaceable things like digital pictures.
    And yes, I have multiple CDs burned at intervals, but I'd still like to
    have them on a different medium as well.) In that scenario, I would
    probably just leave the power and data cables connected to the external
    drive essentially all the time. I can just hear someone say "Yeah, but
    what happens when you fill that drive up and need 2 or more drives?"
    I'll grant everyone ahead of time that is a real possibility. I suppose
    an extra set of cables for each external drive would not add all that
    much more cost though.

    I was actually thinking more in terms of the hot-swap trays one can
    mount in a drive bay, since I always tend to over-build in the area of
    the PC case and have lots of spare empty drive bays as a result. I did
    today finally do a bit of homework and found quite a few of these at my
    favorite internet vendor (Newegg - no affiliation, just a happy
    customer) in the $25 to $35 US range. Several mention being
    "master/slave free" which I'll admit I had not thought about.

    In any case, thanks much for your comments.
    Charlie C.

    >
    > HTH,
    > Paul
     
    CSquared, Jan 5, 2009
    #3
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Don Taylor

    Virus Virus Virus, Was: HOT HOT HOT

    Don Taylor, Nov 1, 2003, in forum: Abit
    Replies:
    0
    Views:
    291
    Don Taylor
    Nov 1, 2003
  2. David H. Lipman

    Re: HOT HOT HOT

    David H. Lipman, Nov 1, 2003, in forum: AOpen
    Replies:
    0
    Views:
    829
    David H. Lipman
    Nov 1, 2003
  3. BoB

    Re: HOT HOT HOT

    BoB, Nov 2, 2003, in forum: AOpen
    Replies:
    1
    Views:
    800
  4. Z.K.
    Replies:
    3
    Views:
    3,549
  5. Paul

    Re: SATA and Hot Swap

    Paul, Jan 1, 2009, in forum: Gigabyte
    Replies:
    1
    Views:
    1,155
Loading...

Share This Page