On Mon, 24 Jun 2013 09:55:46 -0600, paul condon wrote: > I have two 3TB Seagate external HDs. They were purchased from different > stores at slightly different times earlier this year, here in Colorado. > I want them to have ext4 file systems on them, excepting if someone on > this list can give a reason otherwise. I have googled and gotten a lot > of hits, which indicate to me that this is a well known problem. > Unfortunately, I have difficulty following the instructions, and all my > efforts have not reached a successful conclusion. Now with further trys, > it seems to me that stuff has been written onto the drives that needs to > be wiped off because I get messages that from the disk utility in xfce4 > that it won't overwrite a disk with data on it. > > So I want to use dd to wipe a complete drive.
What I do for every new disk before I use it is an exhaustive read/write check with badblocks. It reads and writes every block multiple times with various bitpatterns and random bitpatterns, and check that they can be read correctly. If there's anything wrong with the drive, I return it to the store for a replacement. And yes, I have had to return drives sometimes. Those turned out to have thousands of bad blocks, so good riddance. The process does wipe the drive clean. And you'll find ouot if the drive is defective -- it's just possible that that's part of your problem. Be careful not to do this with the drive that contains your real OS and data by mistake. For drives larger than 2 terabytes, use gdisk instead of fdisk. Read the online documentation first; there are significant differences. In particular gdisk makes all the changes immediately instead of saving them up to write them when everything's done. So there's no leaing things alone by quitting at the end instead of writing, > For this I have found the following: > # dd if=/dev/zero of=/dev/sdg bs=1M In the above, I have already changed > the HD device to sdg (from sda), but I wonder about bs=1M. Could the > process go faster with a larger block size? What are the criteria for > choosing a value for bs? And, how long should a 3T wipe take to > complete? The job has been running for about 12 hours. Would it go > faster with a different bs? Faster enough to make the waste of 12hrs > running worthwhile? Is there some way to invoke an 'progress indicator' > for dd? And, in general, is there a better way? > > TIA paul -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/kql2f1$kju$2...@ger.gmane.org
