Hi Paul On Mon, 2005-01-17 at 12:38, Paul Bijnens wrote: > But you can do just the same using dd: > > dd if=/dev/random of=/dev/st0 bs=32k > > and count how many 32Kbyte blocks get on the tape. > Expect about 15000000000 / 32768 or about 457763 blocks. > > Remember, it takes about 2-3 hours to fill a tape. > > Multiple runs should result in an almost constant number of blocks > (plus/minus a few hundred).
root@:/usr/local/etc/amanda/backup> dd if=/dev/urandom of=/dev/nrsa0 bs=32k dd: /dev/nrsa0: short write on tape device 1301+0 records in 1300+1 records out 42598476 bytes transferred in 13.372441 secs (3185542 bytes/sec) root@:/usr/local/etc/amanda/backup> dd if=/dev/urandom of=/dev/nrsa0 bs=32k dd: /dev/nrsa0: short write on tape device 1756+0 records in 1755+1 records out 57507912 bytes transferred in 18.072619 secs (3182046 bytes/sec) root@:/usr/local/etc/amanda/backup> dd if=/dev/urandom of=/dev/nrsa0 bs=32k dd: /dev/nrsa0: short write on tape device 127+0 records in 126+1 records out 4128840 bytes transferred in 1.362397 secs (3030570 bytes/sec) root@:/usr/local/etc/amanda/backup> dd if=/dev/urandom of=/dev/nrsa0 bs=32k dd: /dev/nrsa0: short write on tape device 1935+0 records in 1934+1 records out 63373386 bytes transferred in 20.628743 secs (3072092 bytes/sec) root@:/usr/local/etc/amanda/backup> dd if=/dev/urandom of=/dev/nrsa0 bs=32k dd: /dev/nrsa0: short write on tape device 354+0 records in 353+1 records out 11567158 bytes transferred in 3.702742 secs (3123944 bytes/sec) root@:/usr/local/etc/amanda/backup> dd if=/dev/urandom of=/dev/nrsa0 bs=32k dd: /dev/nrsa0: short write on tape device 704+0 records in 703+1 records out 23035980 bytes transferred in 7.960560 secs (2893764 bytes/sec) It was a little bit faster ;-) but I guess that's mainly because this drive isn't in a very good shape... at least those rapidly changing numbers look a lot like that. Regards Peter
