On Thursday 04 September 2003 09:35 am, Jerry McAllister wrote: > Hi, > > > I have just installed FBSD-CURRENT on a test box. During install I > > unwittingly installed a BootMgr entry for the second HDD (it will > > just be a data disk, no need to boot from it). > > > > If I do 'dd if=/dev/zero of=/dev/rad2 count=15' will this "erase" the > > BootMgr or will I have to redo Fdisk and etcetera. There is no data > > on the disk yet so this would be no hardship, but is there a "proper" > > way of doing what I want? > > So, if there is nothing to be lost, just try it out and see what > happens. Smoke testing is a tried and true technique. > > Anyway, you really don't need to bother, but yes, that should wipe it. > There are some examples at the bottom of 'man disklabel' that you > might want to check out - even though you really are talking about > fdisk stuff. The fdisk man page is weak, for example it doesn't even > document the -I switch (tho it lists it at the top) which is what you want. > You kind of have to read the disklabel man page in conjunction with the > fdisk man page to make any sense of things, and then it may still take > some experimenting. > > From man disklabel: > > dd if=/dev/zero of=/dev/da0 bs=512 count=32 > fdisk -BI da0 > dd if=/dev/zero of=/dev/da0s1 bs=512 count=32 > disklabel -w -B da0s1 auto > disklabel -e da0s1 > > Completely wipe any prior information on the disk, creating a new > bootable disk with a DOS partition table containing one ``whole-disk'' > slice. Then initialize the slice, then edit it to your needs. The dd > commands are optional, but may be necessary for some BIOSes to > properly recognize the disk. > > Actually, the first dd sometimes fails, if the disk has never had > anything put on it. If so, just ignore it and go on with the fdisk. > > ////jerry
If you have a bootable DOS disk with fdisk, you can clear the MBR without destroying partitions by executing: fdisk /mbr In my pre-FreeBSD days, I used to do this to clear LILO out after removing a Linux installation so that it would boot to Windows. Best of luck, Andrew Gould _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
