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Kyle76 · May 20, 2008, 03:18 PM

Do I really need to drag my USB external hard drives to the trash before disconnecting? I usually just pull out my USB hub.

JKT · May 20, 2008, 03:43 PM

Yes you do*. You risk corrupting the file directory if you don't, which could render your files inaccessible.

* You don't have to drag to the trash - you can right click the disk on the desktop and select Eject "name of your disk", or click the eject button next to the disk in the sidebar of the Finder (if you have chosen to display disks in both locations in your Finder preferences and your Desktop view preferences).

mduell · May 20, 2008, 06:13 PM

Yes or disable write caching (probably through plist hacking, I doubt OS X presents a nice GUI way to do this) and wait for disk activity to stop before unplugging.

jmiddel · May 20, 2008, 08:32 PM

Absolutely you must, as JKT says. Once I accidentally unplugged an external drive, I had to reformat it, and re-clone the entire internal to the external.

Kyle76 · May 21, 2008, 01:42 PM

I have discovered that both of these USB-2 drives are extraordinarily slow when copying files to my internal hard drive. Could I have messed something up? The files appear in finder, but the connection seems to be very slow (1 hr. to copy a 54 mb file). Do I just need to reformat these and start over?

JKT · May 21, 2008, 03:41 PM

You could try running Disk Utility on them to repair the disks. If it finds problems and it can't fix them, then reformatting (assuming they don't contain anything important or vital) would be the simplest thing to do.

analogika · May 21, 2008, 03:45 PM

Are you sure your machine has USB 2? And if so, are you using a white/transparent Apple keyboard or older and connecting the drives to that?

Because ALL keyboards prior to the current aluminium ones only had USB 1.1 hubs built-in.

steve626 · May 21, 2008, 11:42 PM

Originally Posted by Kyle76

I have discovered that both of these USB-2 drives are extraordinarily slow when copying files to my internal hard drive. Could I have messed something up? The files appear in finder, but the connection seems to be very slow (1 hr. to copy a 54 mb file). Do I just need to reformat these and start over?

Even if you are using USB 1.1, that should still be 10 mb/s. A 54 MB file would take about a minute to copy. (A 54 mb file would take 5 seconds.) Obviously your unplugging of the drives instead of ejecting them has caused directory damage and that can dramatically slow down access to files on such a drive (or even make them inaccessible). You should copy your files off and reformat and stop just unplugging without first ejecting the disks.

If you are really using USB 2, then you could get up to 480 mb/s. So your 54 mb file would copy over in less than a second, and a 54 MB file would copy over in a few seconds. Regardless of which USB port you are using, your copies are taking 100's to 1000's times longer than they should, and I am suspecting it is from the damage caused from unplugging a live drive without first ejecting it.

mduell · May 22, 2008, 12:46 AM

USB2 full speed (which used to be called USB1.x) realistically gets about 0.5MBps, and USB2 hi-speed (which most people mean when they say USB2) realistically gets about 25MBps. So we're looking at 2 seconds - 2 minutes to copy a 54MB file, not the hour it took the OP.

imitchellg5 · May 22, 2008, 09:00 AM

He's using a USB hub, which would be an issue.

Kyle76 · 10:02 AM

Originally Posted by steve626

I am suspecting it is from the damage caused from unplugging a live drive without first ejecting it.

If there is damage to the HDD, can it be fixed? I am doing a Time Machine backup for the first time to one of the HDDs in question. The Mac erased and reformatted the drive, but the backup is doing about 1mb every 15-30 seconds.

EDIT: I connected my HDD directly to the USB port, and data transfer is about 100 times faster (rough estimate!). I guess the hub did make a tremendous difference.

analogika · May 22, 2008, 10:45 AM

Out with the hub!

Kyle76 · May 22, 2008, 01:03 PM

Do firewire hubs work better than USB hubs? Do all USB hubs create problems or just certain brands?

analogika · May 22, 2008, 02:03 PM

Firewire and USB are not interchangeable (unless your external drive has both, of course).

There's crap hardware and good hardware in every product segment - hubs, too. My impression is that as Firewire is less widespread, the hubs available tend to be fairly expensive, but decent.

However, some devices may also just not play nice with hubs. I know this is the case with USB; not sure about Firewire.