bb@reef.cis.ufl.edu (Brian Bartholomew) (01/30/91)
Hey, I tried to back up my v2.o system disk tonight, and I ran into a snag. My first thought was to check on the partition table "disk; print label", notice that it was all one partition, and then to a dd | rsh across the network to another drive. Much drive spinning later, but no tale-tale clunks, I decided that it wasn't working. Checking on the od(4) man page mentions that lseek(2) isn't implemented. It also mentions that this implies read(2) is broken. Which implies that dd(1) was copying some random byte into the same place on the target disk, as neither disk was advancing after the write(2). (dd(1) reported that it had written 17 Meg in the meantime, and a ps(1) showed that each dd(1) was snarfing about 5% of the CPU). So, I have two questions: 1) Who broke a perfectly good mechanism like read and write, that would allow me to copy a disk partition? (Granted, only one partition at a time.) 2) How does one XEROX a disk? This is U*IX, master of the byte stream and the transparent device, so "you can't do that" is not an acceptable answer. Neither is "you can't do that because you will duplicate the bad block mapping as well". Can someone shed some light on this? -- "Any sufficiently advanced technology is indistinguishable from a rigged demo." ------------------------------------------------------------------------------- Brian Bartholomew UUCP: ...gatech!uflorida!mathlab.math.ufl.edu!bb University of Florida Internet: bb@math.ufl.edu