Hi, Gene Heskett wrote: > Is bash not actually bash these days? It is not doing for loops for me.
Come on Gene, be no sophie. Copy+paste your failing line here. :)) IIRC the for-loop in question writes several copies of the same file. ( https://lists.debian.org/debian-user/2024/02/msg00318.html ) Others already pointed out that this invites for firmware scams like deduplication or silent overwriting of older data. I would vote for a filesystem killer like shred -n 1 -s 2047999968K -v - | tee /dev/sdm1 | sha256sum dd if=/dev/sdm1 bs=32K count=63999999 skip=32 | sha256sum But shred(1) on Debian 11 refuses on "-" contrary to its documentation: shred: -: invalid file type A non-existing file path causes "No such file or directory". The filesystem killer aspect could be removed by creating large data files in the readily partitioned and formatted filesystems of the disk. (Replace "/dev/sdm1" by "/where/mounted/random_test_file" and reduce the numbers 2047999968K and bs=32K count=63999999 to what you expect to fit into the filesystem. Like 2000000000K and bs=32K count=62500000. Ask df for storage capacities.) But there needs to be a fast pseudo-random byte stream (which shred would provide if i could talk it into writing to stdout) which you can split for the device and for sha256sum. I have an own weak-random generator, but shred beats it by a factor of 10 when writing to /dev/null. Have a nice day :) Thomas
