Got it. tar -tvb 240 -f /dev/tape0n | more
lists the files. I did some searching and found that the error (cannot allocate memory) sometimes shows up when the block size is wrong. For dd dd -if=/dev/tape0n -of=archive1 bs=240b did it. Thanks for the help. I got to delve a little deeper into tar, dd, and the tape. On Tuesday February 7 2006 10:20, Richard Fish wrote: > On 2/5/06, Brett I. Holcomb <[EMAIL PROTECTED]> wrote: > > Okay, I think I figured out what they are doing. They have a bunch of > > files for the labels. If I move forward using asf n where n is a number > > from 1-n I can walk through the label files. They take two files/label > > file so I go from 1 to 3 to 5 .... > > > > # dd if=/dev/tape0n of=archive1 bs=10k > # dd if=/dev/tape0n of=archive2 bs=10k > ... > # dd if=/dev/tape0n of=archiveN bs=10k > > This should give you a dump of all of the data on the tape, and then > you can analyze it in more detail. You might have to fiddle with the > bs= value above though. > > For some background info, tape devices generally write file marks > between archives. So as long as you are using the no-rewind tape > device and reading the full archive, you can usually just read them > one after the other. The mt fsf command is mostly useful for skipping > over archives. > > However, tape devices are not very consistent. Sometimes if you read > just part of an archive and close it, the tape will automatically move > to the next file mark. Other devices will require an mt fsf command > to get to the next file mark. > > The asf command sometimes works, and sometimes doesn't. rewind and > fsf is the safest method. > > -Richard > > > On Sunday February 5 2006 23:36, Richard Fish wrote: > > > On 2/5/06, Brett I. Holcomb <[EMAIL PROTECTED]> wrote: > > > > I have a scsi tape library and a backup program that creates datasets > > > > of tar files on the tapes. I gather each dataset is a tar file. I > > > > would like to be able to access each of these tar files. At this > > > > point I can tar -tvf /dev/tape0 and see the file that contains the > > > > tape label. But I can't get beyond that. I've tried skipping to the > > > > next file, records, set mark using mt with no luck. > > > > > > mt is the correct command, but you need to make sure you are using a > > > no-rewind tape device (ntape or nst0). Otherwise you will end up > > > seeking to the next file, closing the file descriptor, which causes > > > the driver to rewind the tape. > > > > > > -Richard > > > > -- > > > > Brett I. Holcomb > > -- > > gentoo-user@gentoo.org mailing list -- Brett I. Holcomb -- gentoo-user@gentoo.org mailing list
