[rotuts]

Ive had some problems copying to an external firewire HD. its 2 TB and has 70 GB 'free'

this is from the main MacPro to this Hd.

I get the message: 'Operation cant be completed "File" is in use' the file is the file being transfered.

then the HD wont unmount, and I get the message HD is in use. try quiting aps.

there is a partial file on the HD .

I have to turn the HD off, but it remounts fine. Disk first aid says at this point all it OK

but before the forced turn off, DFAid says it cant unmount the HD

what's happening? could it be that this HD has 'bad sectors'?

many thanks for any and all help!

[reader50]

According to those numbers, your external is 96.58% full. Unless everything is perfectly defragged, that 70 GB free is probably scattered across the drive in hundreds or thousands of fragments.

Get a bigger drive, or another drive, or clear some space. HDs won't work reliably when they're this full.

[rotuts]

this makes a great deal of sense. on the other hand, this is the first time Ive gotten these messages and most of my 2 TB drives are almost completely filled, up to about 2 TB

this drive is 'new' and no files placed on it have been deleted, so I cant say much about fragmentation as i have no experience with it.

what messages might i get if there were 'bad sectors'

Ill copy all the stuff over to a brand new HD and then reformat this one eventually.

many thanks for your help and insight.!

[reader50]

If a bad block is encountered upon Write, the drive maps a spare block into play and re-writes the data from buffer. You don't see an error message at all, just a slight delay during the last write.

If a bad block is encountered upon Read, the drive will try to pull the data for some time. Repeatedly trying to read the block. Maybe it'll get enough data for error correction to reconstruct the full block. Otherwise, it'll eventually give up and report "There was an error reading xxx file."

[rotuts]

thanks for both your expertise and time.

these last few files do indeed pause on 'write' or at least what I see as write. then seem to give up and i have an incomplete file on the target HD, which causes unmounting problems

none of the issues are on 'read'

[reader50]

Delays on write can be caused by other things. If your free space is heavily fragmented, you will have long write times. The OS will be putting small pieces of your file in every empty space it can find. Then updating your extents file with the fragment list. Possibly trying to find space for the extents file to grow too.

Once drives go above 95% capacity, their performance can crash rather suddenly. Using a drive regularly above 90% will lead to heavy fragmentation over time. The usual rule of thumb is to stay below 80% on a working drive.

Under ideal circumstances, you can fill a drive to 99%, say for archive purposes. But circumstances are not always ideal. I'm not surprised that it has worked for you, and not surprised one drive is giving fits. This does not indicate bad blocks - you're just pushing the envelope.