Dangers of simply pulling out USB devices

What am I risking if I pull out a USB device without doing the "Safely Remove Hardware Step"?

Is it a problem if:

1. A am not doing anything with the device, it's only connected
2. A file on a device is open
3. I am copying something from the device (same as #2?)
4. I am copying something to the device

?

Thanks in advance!

 

What is the OS, that is the important question.

 

1. Nothing.
2. Nothing.
3. Copy could become corrupted; not advisable.
4. See #3.

 

1. No
2. Only if you want to save it
3. Corruption possible.
4. Corruption possible.

If you're on Windows, you'll get a message only if something went wrong. If you're on OSX, you'll get a message no matter what... explaining how much of an idiot you are for taking out the device why did you pull it out without ejecting first it's an easy to use operating system you made it angry and now it will whine and complain why would you do that oh my god it's a beachball but at least it's shiny too but seriously don't do that again

 

I'd add that if it is a mechanical rotating HDD then pulling the power will activate the emergency head retraction mechanism. This has a projected life of 250-500 activations, depending on HDD manufacturer. I'm not even talking about physically moving the HDD, just yanking the power and the emergency head retraction mechanism coming into force....

Storage Forums

 

While I completely agree with the above, I would still first release it properly... I do it 90% of the time, but sometimes when I'm in a hurry or Windows tells me it is not possible for some reason I can't see I just pull it out...

This is not exactly true. Could be true only if the HDD is spinning and in use (copying in process, etc.). Otherwise even if you release it properly it does not stop spinning, it just denies further access to the file system. Also when left in idle long enough it stops spinning and it is absolutely safe to pull it out.

 

you mean as long as it is a windows 7, he is ok

 

I've simply pulled USB drives out for years and years without even knowing they could be manually ejected until around a few years after Windows XP came out. Never had a problem with corrupted data ever.

 

I have seen USB thumbdrives become corrupt just by being idle and just yanking it out over XP, Vista, 7.

Why not take the 3 extra seconds to safely remove the USB device..

 

because in all others the added flash storage is considered fair game for disk cache. in win 7 you have to program it

 

The problem is whether your system mounts the external drive synchronously or asynchronously. Windows by default mounts USB drives synchronously, so when a copy dialog closes the copy is actually done. Some drives may not be mounted that way though due to various system configurations, and may be mounted asynchronously. That means the whole copy is read and cached in memory, but may not actually be physically written to the external drive.

By default Ubuntu (and possibly OSX, I don't know) mount USB storage asynchronously so copies happen faster, but that requires you to unmount the drive, otherwise you will get corrupted files or possibly an entire filesystem. So my general advice is to always "safely remove" or unmount USB devices. That way you know it's clean.

 

I have once corrupted a flash drive so that it only showed up as a 0-byte drive afterwards, even though it was not in use when unplugging (or so it seemed).

 

The main point here is that NO ONE can tell if your host OS is doing any writes or housekeeping to an attached mass storage device regardless of the interface.

Always go through the eject procedure. Always. It's the ONLY way to be sure.

 

USB devices send a message to the OS indicating what kind of device they are, and there is a differentiation between removable and hard disks I believe.

I've never used Safely Eject Hardware unless I'm unsure whether something is done copying over, which is perhaps 5% of the time. I've never had a drive die from corruption yet.

 

Since getting Windows 7, I have been neglecting to do the Safely Ejecting method. However, I had two flash drives get corrupted when I was on Vista and XP. I have a feeling it was due to unsafe ejection, but then again, they were cheapo flash drives.

However, when I do pull my mechanical external hard drives, I make sure that they stop spinning and making noise before I unplug. However, I think I should get back in the habit of clicking the actual button to eject to ensure that I don't break my HDD as sometimes external HDD's will keep spinning even at idle at times.

 

I am with you man, I work on PC's for a living, so I tell everyone that asks to yank them at will. I would never do it myself, but I am always looking to drum up business B4 the US economy collaspes.

 

LOL. At least you are a honest man...

 

Those are due to the open file handles.

When some programs access the external devices they don't dispose the handles properly and even though you think that you don't access the external drive Windows still thinks that the drive is actively in use. Therefore Windows does not say "You can safely unplug the device."


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My understanding is that if its a flash drive you want to do the safe eject due to how files are stored.

But if its a mechanical drive, unless its writing to the disk when you pull it, its fine.

In my experience this has held true. I have pulled external drives out numerous times and never had a problem, but I have had 2 usb flash drives just go dead on me. One right after pulling it from one computer and going to put it in another to transfer a file. The other was something similar.

I always do safe eject now for both, with the mech disk more or less just to make sure the head has properly disengaged from the platter to not damage it, and for flash drives to not break them or corrupt all the data.

 

I would like to see you do it on Linux with your important data.
Linux do not flush data fully after you copy (By default).

 

and put it on youtube, I love watching the raging videos.

but seriously, drivers thats how windows can detect which is which