> 1. boot up knoppix > 2. create a partition: mkdir /work > 3. mount /work to the root partition: mount /dev/sdc /work > 4. cd /work/usr/bin > 5. run dcfldd: ./dcfldd
This is fine, provided that 1- if the root partition is [part of] what you're copying, you *must* mount it read-only (mount -o ro /dev/sdc /work) 2- the dcfldd executable is linked statically. If it uses dynamic linking, your "live" system -- knoppix in this case -- must have exactly the same library versions (especially glibc) as the gentoo system. >> Or is there a way to do such copies from a one disk to another while >> one disk is booted??? The point is not with being "booted" (i.e., part of the running system) or not: you *cannot* reliably perform a sector-by-sector copy of any write-mounted partition without special support either at the FS or block device level (i.e. snapshots). > Sure, but the running disk/sector would have temporary files that would > not consistently hash when you did the hash check. That is only a minor part of the problem. The real issue is that if *anything* writes to the source partition while you are halfway through copy, you risk ending up with inconsistencies in the filesystem metadata. Doing a fsck on the copy will probably fix that, but you risk losing or corrupting data. And no, hashing as described in the previous post will *not* catch any differences in this case, as the "source" hash is computed from what is read during the copy (which, barring hardware problems, is what gets written on the target disk) and not from the whole contents of the source partition after the copy (or at any single point in time). > If you do this, try it in linux without bringing up X. That's definitely not enough: at the very least, boot up in single-user mode and remount all your partitions read-only (mount -o remount,ro). This will break things on a running system (e.g anything that writes to /var and /tmp will throw errors or stop working), but it will allow you to produce consistent partition images. andrea
