USB Safely Remove is the utility I use.
If a process is writing to the drive when the plug is pulled, some undesired things can happen.

"My experience is that even pulling a usb drive without formally telling Windows doesn't cause any harm."

That's just asking for trouble.

This is a subject way too difficult to generalize about. Plug-n-play, USB implementation on motherboard, and USB implementation on external device, vintage of the driver sets all play a part in the connectivity of device and exit calibration. AND this is not too mention designed hot-plug hardware implementations, Esata, and Firewire connectivity are yet even other problematic situations.

What you can "safely" do is not a hard and fast kind of rule you can just set to print.
All depends on the system.

"How do you Safely Remove External HDD ?"

Unplug it.

You do not need to "eject" or "safely unplug" any spinning HDD. The command does nothing. It is a good practice to power it off before moving it, though.

The reason you need to "Safely Remove" a USB thumb drive is because windows does not write data to the thumb drive as it comes into the I/O buffer. Data going to the thumb drive gets written when the buffer is full (normally 2Kb), and when you hit the "Safely Remove" button. (A normal PC shutdown will also flush the I/O buffers to the USB drive). There are ways a program can force a write, and Windows will also periodically empty the buffer into the thumb drive. (I believe the default is 1000ms, but don't quote me). This last point is why problems with incomplete files on the thumb drive are pretty rare.

last weekend I plugged a usb drive into someone's mac and it crashed their premiere...yeash...I think these guidelines are more targeted to mac users but it's still a good practice.

I don't get why you wouldn't just eject the drive anyway, it just takes a second.

I've had thumbdrives killed dead by yanking them out at whim. I've also lost the contents of SD cards in phones this way. Now, I go find the Eject or Safely Remove command and then I wait after I've used it. The pain of losing 8GB of content is greater than the pain of counting to ten.

Several of my thumb drives have lights and they'll often go on blinking after windows has said they were safe to remove. I wait.

Rob

I will side with Steve Mann here, you do not need to go to any lengths to remove a rotating type hard drive.

A more important issue is to not shock the drive when running or moving it. Any of the USB style 2.5" drives are designed for portable devices such as laptops and are ruggedised to a degree. As soon as you remove power, the heads automatically park and the drive spins down.

I always place my drive on the top of the computer case and leave it there when running or inserting/removing the USB cable. I give the drive time to spin down when removing it, but typically it only requires 3 to 5 seconds.

@Steve Mann >> Unplug it

This is incorrect, but not necessarily for the same reasons that you should not do this to a thumb drive.

1/ Data may be buffered, even on a spinning disk. but unlikely...
2/ and this one is important, an application may have a file open for writing on that disk, and if the app is not finished writing to it, the file data for that specific application may be corrupted. Nobody knows how any specific app stores data in files, and it is quite possible, or even probable, that an incomplete write will leave the file completely damaged.

The OS will stop you from "ejecting" a disk that is still being written to. If you keep yanking drives on active systems, sooner or later you are going to be in trouble. The app may not even be an active app but some sort of service that some app/installer installed, so no active apps is no guarantee.

Just eject the disk, once that is OK, yank it. No need to worry.

Guess I've been very lucky.. I've NEVER ejected a drive be it SD cards, solid state, thumb, 3.5 or 2.5 and have never had a problem.

BUT my knee snagged the a drive USB cable dangling off the front of my desk when I spun around and the 2.5" drive took a dive to the floor. Needless to say the drive was toast Windows could not recognize it. I was able to recover the data by pulling the drive out of the case attaching it to a universal drive adapter and connecting it to a Linux box. For some reason the drive case USB - SATA adapter would not work, so after messing w/ the drive by powering it down/up connecting/disconnecting the adapter a few times, Linux was finally able to see the files on the drive and recovered all of them. *whew* Good lesson learned, never leave USB drive cables dangling off the front of one's desk! (:

I agree with Terje for the reasons he stated. In my experience I've seen file corruption more than killing the device however both do occur and seen it numerous times at work.

Those that have never experienced or seen it perhaps use an external drive as a general means to just move media around. I'd say in that scenario it is very unlikely to have the OS have a file handle open as you are just moving stuff around. Here is a something that happened to numerous colleagues at work. When testing applications or new software we ran virtual machines and people copied the VM images to external drives. During the day they would mount that image from their external harddrive and forget they had a VM session open when leaving for the day. The next day they find out the image is toast and need as new copy. This happened quite often actually.

Also when the OS says it is not safe to remove that is because something is connected to a file(s) on the device. Ignoring that can cause a corrupt file however many times it is just fine. An example would be if you opened a photo in a paint program. Breaking that handle should not cause damage as the data has been read and loaded and nothing is expected to be written back. Another common cause for saying a device can't be removed is Windows explorer is open with the external drive as the view you are looking at. It seems that newer versions of windows handle this more gracefully but can be an issue for older versions (Vista / XP). If you are unsure and the data is important that simplest thing is to shutdown and reboot.

Hi,

Thanks for many input... well, so far I safely remove them first, but wait a short while before disconnecting the hardware too, and seems safe.

Just make sure there are no more activities in the drive itself to disconnect or even moving them after disconnect it.

Assuming FlashDisk and SD cards are similar one, in several camcorders like VG20, VG30, VG900, HXR-MC1500, HXR-MC50, when you shutdown the camera, it didn't shut down *right away, there still several process for few seconds, and then shut down. (perhaps something like closing a media or else)*

*Correction

Hmmmm.... the discussion seemed to be about external HDDs and now you mention various cameras not shutting down properly. I am not familiar with the cameras you listed however am wondering if you are having trouble with the recordings? Is the media damaged and you can't read it or are your cameras just not shutting down normally however the media is fine? Perhaps others can chime in about these cameras.

The danger or just yanking any external drive is that if files are being written to or in an open state corruption may occur. When people lose all their data it was probably removed during a write operation. If you've closed your applications, including any Explorer windows, you are most likely safe to disconnect, but to be even safer I use the Safely Remove Hardware Systray app. When it says you can safely remove media, you know that any connections to it have been closed.

"1/ Data may be buffered, even on a spinning disk. but unlikely.."

Not possible. The spinning HDD have the buffer on-board, not in system RAM. The data is written to the disc platter as soon as the buffer gets it. We're talking write-cycles. Nanoseconds of delay.

Any NV-Ram device relies on system RAM for its' buffer, which is why it needs to be dismounted. (Ejected).

"2/ and this one is important, an application may have a file open for writing on that disk, and..."

Then the problem is with the user. If you yank a drive while data is being written, you will lose data. The type of drive or how data is buffered is irrelevant.

skosh, your observation is correct, I ONLY use external drives to archive and xfer data. In the rare instance data is updated on the drive, I only remove the drive after the app or file is closed.

I never run programs/apps from external drives because the drive letters sometimes get mixed up after another drive is added and the app is dead.

I have had an error message when plugging a HDD in along the lines that it had not been released properly, and offering to fix it for me. (Reminded me of the Unix dirty file message after a power failure.)

Some devices such as still cameras do not appear in the list that shows up when you click on the USB icon in the tray. I just unplug and all seems to be well.

I have other hardware that accepts USB drives but they don't appear to have a safe remove option. I only remove drives from my media power after it has been shut down. (I think I had a problem once with hot removal, but not sure now.)

I recently plugged a USB hard drive into my TV to play some video files. After finding it a bit clumsy (the files were in reverse order) I merely unplugged the drive with the TV still powered up, since I couldn't find any safe release procedure in the manual. After that, the drive would not play on my computer, so I broke the case open to extract the drive inside, and was gratified to find that the disk itself was undamaged; only the USB to SATA converter. Coincidence?

skosh: ...now you mention various cameras not shutting down properly.

Hi Skosh, these camcorders are doing this. No problem with the recordings.
Other cameras and DSLRs is shutting down right away after you turn off the camera... These are normal process and mentioned in the manual. - Edited my post above...

PeterDuke:
I recently plugged a USB hard drive into my TV to play some video files. After finding it a bit clumsy (the files were in reverse order) I merely unplugged the drive with the TV still powered up, since I couldn't find any safe release procedure in the manual.

>hmmm, this is not good...., except shutting down whole system totally to be very sure... I even seen new TV Display, with USB3 HDD connection mentioned. Looks like the TV makers must add this feature for the sake of safety...
Even PS3 doesn't have safe eject for Flashdisks. So, I must make sure that no activity, or not in the middle of playback, when ejecting it.

The reason why the TV set manufacturers don't provide an 'eject' facility is because it is not necessary. a TV set does not write to the disk, it only reads it, therefore just pulling the connection is all that is required.

I have a small LaCie 1TB USB drive that I connect to the TV on a regular basis and I have never had any issues with it. When you remove the connection, the drive simply parks the heads and powers down. If it is playing back at the time it will not be a problem, except the TV might get confused.

You don't need to "eject" a drive.

If you go to the drive properties (the policy section) you can set the drive for "performance" or "quick removal".

If you set for "quick removal" it disables write cacheing and as a result there is no need to use the safe removal tool (as stated right in the policy description).

Any portable drive that you use should be set for "quick removal"

And for the record.... I've just yanked my drives for at least the last 15 years and haven't had a single issue in that time.