aegl@root.co.uk (Tony Luck) (12/16/87)
In article <10773@brl-adm.ARPA> rbj@icst-cmr.arpa (Root Boy Jim) writes: >by default. Now I type `dd<rhp0a>rhp1a bs=16k' instead of the brutally ^^^^^^ I was bitten a while back (on 4.1bsd) by the 'up' driver which silently forgot about the last partial transfer that should happen when you use the above command (an 'a' partition has 15884 sectors so if you use a block size of 16k you should do 496 whole transfers and one itsy little transfer of the last 10 blocks). Everything was ok until some of those last ten blocks got allocated for a directory! I don't think this should be a problem on 4.2 or later because the fast filesystem tends to ignore a bunch of blocks in the last cylinder - and besides the bugs in the driver may have been fixed. But if you don't trust your driver and you think you might want *all* of your disk copied pick a buffer size that is a factor of the partition size. (use /usr/games/factor - unix seems to throw in utilities to help you work round the bugs in the rest of the system!) -Tony Luck