Billy Davis wrote: > We are running Centos 5.6. All was fine until yesterday. I attempted > to tar a 14KB work file to a USB floppy (/dev/sdb) for transport to > another server. Unfortunately, I keyed in 'tar cvf /dev/sda filename' > instead of 'tar cvf /dev/sdb filename'. /dev/sda is our main > (boot/root/apps) scsi hard drive. I realized my mistake, but it was > too late. The system is still powered up and running, but I am sure > that I have overlaid (and trashed) the mbr and the disk directory map. <snip> > I suspect that when I power the system down, it will not reboot. I can You have that right. > reinstall mbr and grub, but I don't have the original partition table > start/end values. Since the system is still running, it seems that the > partition table must still be available to it from somewhere. > > Is there any way to easily restore the partition table? Easily? No (other than the grub-install /dev/sda part). Sorry about your problem, but I appreciate the question: it led me to <http://www.cromwell-intl.com/unix/linux-kernel-details.html>, a fair bit of which was quite familiar, and other bits weren't. For example, cat /proc/partitions might give you a serious bit of the information you're looking for. Hope that helps. mark