Am 13.02.2012 16:31, schrieb Grant Edwards: > On 2012-02-13, Michael Orlitzky <mich...@orlitzky.com> wrote: >> On 02/13/12 05:49, Helmut Jarausch wrote: >>> >>> I've written a small Python program which outputs the file names in >>> i-node order. If this is fed into tar or cpio nearly no seeks are >>> required during copying. >> >> What makes you think the inodes are sequential on-disk? > > Even if the i-nodes are sequential on-disk, there's no reason to think > that the data blocks associated with the inodes are in any particular > order with respect to the i-nodes themselves.
You could probably find the intended order by using debugfs (at least for ext*). The following command should output the first physical block of every file: find /var/db/portage/ -type f -printf 'bmap <%i> 0\n' | sudo debugfs /dev/mapper/vg-portage Todo left as an exercise to the reader: - Clean debugfs output - Map inodes back to file names (hint: don't use debugfs's 'ncheck') - sort | cut | xargs cp Possible further improvement: Sort the files so that the first block of the next file is close to the last block of the previous file. Regards, Florian Philipp
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