Am 06.03.2011 um 15:28 schrieb Ashley Aitken:
I could not use Disk Utility to do a block copy of this disk (for some reason it would stop and hang the app or machine part way through). This was during the hot period and the disk could have been overheating during the operation
If the disk is subject to overheating, get it cooled. Often this is a simple as unmounting it from the housing and let it dangling in fresh air. Not a long term solution, of course, but totally sufficient for doing a copy. Cooling a disk usually usually makes it operational again.
Copying the raw device with "dd" is a good idea, as this reduces reading head movement to a minimum. IIRC, copying a raw device to a file gives you something you can convert with diskutil to a valid DMG. Please don't nail me down to the details, it's quite some time since I've done that last time.
If the disk still overheats, you can use "dd" to copy in smaller chunks. Read 10 MB, sleep a second, repeat. Takes some time, but gives reliable results.
In the worst case, you have to instruct "dd" to fill sectors with read failure with zeroes. So you loose only a few single sectors instead of entire files. Beware, "dd" simply drops sectors with read failure by default, making the copy useless. But there are switches to avoid that.
Markus - - - - - - - - - - - - - - - - - - - Dipl. Ing. (FH) Markus Hitter http://www.jump-ing.de/ _______________________________________________ MacOSX-admin mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-admin
