From: Twayne on 14 Jun 2010 12:32
Frank Martin <fm(a)general.com.au> typed:
> "Paul" <nospam(a)needed.com> wrote in message
>> Frank Martin wrote:
>>> The following is copied from the Seagate web page.
>>> Does it mean I can connect/disconnect the HDD while the
>>> computer is running?
>>> 4.0Serial ATA (SATA) interface
>>> Barracuda 7200.12 Serial ATA drives incorporate
>>> connectors which enable you to hot plug these drives in
>>> accordance with the Serial ATA Revision 2.5
>>> specification. This specification can be downloaded from
>>> www.serialata. org.
>>> Or does it mean I can only connect/disconnect the data
>> I've tested it and it works fine. But I don't use the
>> feature regularly, due to the rats nest of wiring
>> inside my computer.
>> For the OS to recognize the drive, you'd want the
>> of the Intel AHCI driver. I tested using a VIA chipset,
>> whatever driver VIA offered, seemed to support "hot plug".
>> Bottom line, there is at least one kind of driver in use
>> for SATA, where hot plug is not recognized, and the drive
>> in that case, would only be seen if it was present at
>> up. If the wrong driver is present, the drive will not be
>> seen after hot plugging it.
>> The main issue with hot plug, is shock and vibration. You
>> don't want to shake the drive while fiddling with cables.
>> The SATA connector on the back of the drive, is actually
>> designed for SATA backplanes. In other words, the intent
>> for a drive to slide on rails, and seat against a mating
>> on a backplane. The SATA connector was designed for server
>> configurations and hot plug - usage as a consumer drive
>> in desktops is an afterthought.
>> (A SATA backplane, where drives would slide in on some
>> kind of carrier.)
>> But you can still use cabling and do the same thing as
>> a server backplane would be doing.
>> This is the order I'd suggest, for manual hot-plug
>> 1) Connect data cable to the hard drive. This is to
>> avoid shaking the drive end.
>> 2) Connect power cable to the hard drive. You should
>> be able to do this step as you wish. If you're using
>> an extension power cable, you can connect the far end
>> to the power supply, as step (2b). Or, if the power
>> comes straight from the power supply, you can just
>> connect it
>> to the drive. (See also, Step 10 below.)
>> 3) The drive starts to spin, once the power connector is
>> in place.
>> You don't want to shake it, after this point in time.
>> 4) Connect the far end of the data cable, to the
>> connector. Look at the connectors on each end, for the
>> "L" shape, to make mating easier. There will be a
>> "dimple" or
>> retention feature on the SATA data cable, to make it
>> fit snugly,
>> so it won't fall off. You have to be able to tell the
>> between the resistance the dimple will offer, versus
>> the stupid "L" upside-down. Don't try to force it on
>> the wrong way.
>> 5) If the AHCI driver is running, or a chipset driver
>> known to support
>> hot plug is in place, the drive will now be detected.
>> If there is a
>> valid partition on it, you'll see that partition added
>> to the contents
>> of the "My Computer" window. If the drive hasn't been
>> yet, you should see a new drive in Disk Management, and
>> you can
>> partition it there.
>> 6) You'll notice a "Safely Remove" icon in the tray. There
>> is a list
>> of removable devices in there, and your new,
>> hot-plugged hard drive
>> will be one of the items. If you happen to see the C:
>> drive in the
>> list, don't panic - you can't remove it, even if you
>> Now, to remove the hot-plug drive later, you can either do
>> a regular
>> shutdown from the Start menu, or you can "hot-unplug".
>> 7) Make sure no programs have open files on the hard drive
>> in question.
>> Use the Safely Remove icon, to select the drive from a
>> list of
>> removable drives.
>> 8) Safely Remove will either tell you the drive is now
>> safe to remove,
>> or that it could not remove the drive. You'll be able
>> to remove the
>> drive, once all opened files have been closed. If you
>> were using
>> Notepad to read a text file on the drive, quitting
>> Notepad should
>> close the connection to that file. Some programs can be
>> very sneaky,
>> so this step can be hard to do.
>> 9) If "Safely Remove" reports the drive was removed, you
>> unplug the data cable from the motherboard end. That is
>> to avoid
>> shaking the drive. If you were to unplug it from the
>> hard drive end,
>> there would be some shock applied to the drive
>> mechanism. In
>> step 9, the spindle is still spinning. In theory, you
>> should be
>> able to tell a drive to spin down, but I don't know of
>> a way to do
>> 10) What happens to drive power now, is a tricky bit. If
>> you were using
>> a power extension cable for the SATA power, then you'd
>> the far end of that. That is to avoid shaking the
>> drive. If the
>> power connector is coming straight from the power
>> supply, I'd
>> personally, wait until the next shutdown, to retrieve
>> the drive
>> and remove the power cable. So using an extension
>> cable for the
>> power, is the most flexible option.
>> As far as I know, you can do anything you want. But if you
>> want a
>> long life for the hard drive, I recommend doing things in
>> such a
>> way, that the drive is not shaken while the spindle is in
>> With the appropriate extension cabling, that isn't too
>> hard to
>> arrange. I expect on servers, they just rip the drive out
>> with the
>> spindle still in motion. There is no way to know, whether
>> heads were parked by "Safely Remove" or not, or whether
>> retracted by the loss of power being detected. On my
>> it was still spinning after "Safely Remove". And I can't
>> if the heads were parked at that point or not.
>> I used one of these extension cables for power, so I could
>> the far end of the power connection at the end of a
>> "session" with
>> a drive. The drive sat on a platform, next to the open PC.
>> I would
>> unplug the Molex 1x4 end, to remove power, leaving the 15
>> pin end
>> seated on the drive. I have enough slack in my power
>> cabling, that pulling the Molex apart doesn't strain the
>> (1x4 Molex to 1x15 SATA power extension cable)
>> If you use an external "ESATA" enclosure, those have their
>> power supply. That gives slightly more freedom regarding
>> shaking things. ESATA connectors have a better design,
>> raises the number of insertions before connector wearout
>> to about 5000 cycles. But your computer needs an ESATA
>> on the back with a connector, or the addition of an ESATA
>> if that is missing, if you want to use ESATA. The ESATA
>> spec is almost the same as regular SATA, except the
>> electrical levels
>> are shifted a bit, to make it possible to use a longer
>> cable (allows
>> more loss budget). If you're using an ordinary SATA
>> connector, and some kind of passive cable and adapter
>> plate, simply
>> reduce the length of the external cabling for best
>> results. You can
>> buy ESATA cables in various lengths.
>> This is an example of a short ESATA cable, at only 0.5
>> meters (1.64 feet).
>> If your computer has "real" ESATA electrical levels, the
>> cable can be
>> 2.0 meters long. If in doubt, keep it short.
>> One of the benefits of using an ESATA enclosure, is you
>> can keep
>> the side of your PC closed (at least, as long as you have
>> ESATA connector on the back of the computer to use for the
>> data connection).
>> If you suspect the data cabling you bought is crappy, you
>> have the option of fitting the "Force150" jumper on the
>> of the Seagate drive, to drop the cable rate to
>> 1.5Gbit/sec versus
>> the 3.0Gbit/sec it is capable of running. If you were
>> seeing problems
>> with data errors, that is something you can try. That will
>> next to no difference to transfer performance, so isn't a
>> big deal.
>> I've tested a couple Seagate drives here, with that jumper
>> in or
>> out, and can't really tell the difference.
> Many thanks for this info. Given the above, my plan is to
> install a multi-pole switch on the computer case, close to
> the drive, to cut the power to the HDD in question, and I
> will simply leave the data plug connected.
> The whole purpose of the excercise it to stop the drive
> spinning when it is used rarely, such as for backups. This
> should prolong it's life and make it immune to power surges
> from failed power supplies, an event I suffered once when
> the HDD control card was cooked.
Actually, no it won't protect the drive if the power connector isn't also
disconnected. Personally I'd just use power management to shut it down after
x minutes of inactivity and forget about it. Depend on the switches to break
both the power AND data lines for long periods of time; then and only then
is it completely protected from surges and spikes.
From: Paul on 14 Jun 2010 16:28
> It's OK, excepting one point: If you disconnect it when there are still data
> to be written to the disk, that data is going to go missing. Unless you kill
> the wrte-behind, data can sit in buffers a very long time before it's thrown
> to the disk. It's always best to follow the instructions.
Using "Safely Remove" should flush any caches.
And if a software path didn't exist to do that, we couldn't
cleanly shut down computers. So it's got to be there.
From: Twayne on 16 Jun 2010 13:06
Paul <nospam(a)needed.com> typed:
> Twayne wrote:
>> It's OK, excepting one point: If you disconnect it when
>> there are still data to be written to the disk, that data
>> is going to go missing. Unless you kill the wrte-behind,
>> data can sit in buffers a very long time before it's
>> thrown to the disk. It's always best to follow the
> Using "Safely Remove" should flush any caches.
I interpreted your query to mean you weren't using that; you just wanted to
hot swap and you mentioned nothing else.
> And if a software path didn't exist to do that, we couldn't
> cleanly shut down computers. So it's got to be there.
lol, no idea what you meant there. It exists for a couple other things, but
neither of my external terabyte drives show up in Safely Remove. It's just a
piece of code, which does whatever its author wants.
It will be there, you're right, IF you haven't set the drive to not need it.
Once you set the buffers to immediate write, it should no longer show in the
Safely Remove... window. It follows that logic on my machines, but I've
heard of others where it still appears in the window.
From: Doum on 29 Jun 2010 06:54
=?Utf-8?B?QW5kcmV3IEUu?= <eckrichco(a)msn.com> �crivait
> In most cases,very few desktop boards (pcs),have the ability for
> hot-plugging...Even if the SATA hd might have such a connection,the
> MB would determine if its available,read the owners manual..Hot
> plugging really is only used by server boards that have 6 or more hd
> running,if one goes out,another is plugged-in,the board,software,& a
> array of hds.
I thought most modern/recent motherboards should support hot plug SATA
drive with the right OS (Vista/Seven)
When I click on the "Remove Hardware" icon on my Core2Quad running Seven,
all USB and SATA hard drives show up for disconnection even internal ones,
there are 4 SATA and 2 PATA HD in that machine. The motherboard is an Asus
P5Q which I think is a "consumer" board.
On the other hand I have a P4 with XP and I installed an eSATA backplate,
on that one I can fire up an external SATA HD and XP recognizes it but I
wouldn't turn it off without shutting down the computer because hot plug is
not supported on that machine and external SATA HD don't show up when I
click the "Remove Hardware" icon.