At Thu, 05 May 2011 10:10:52 -0400 CentOS mailing list <centos at centos.org> wrote: > > On 05/05/2011 08:01 AM Brunner, Brian T. wrote: > > centos-bounces at centos.org wrote: > >> At Thu, 05 May 2011 07:44:52 -0400 CentOS mailing list > >> <centos at centos.org> wrote: > >> > >>> > >>> On 05/05/2011 07:13 AM, Timothy Murphy wrote: > >>>> Is there a standard way of copying a working system > >>>> from one machine to another with different partitions? > >>> You could also utilize cloning software, such as the client version > >>> of drbl, clonezilla livecd. > >>> > >>> You could also do a direct copy with dd onto a connected drive. > >> Warning: dd is not a good choise if the source and desination > >> drives/partitions are *different* sizes. > > > > Different block mappings will also give you grief. > > .:. The drives must be identical manufacturer and model, down to the > > firmware revision. > > dd is not a backup tool in the general sense. > > I had doubts about dd also. But last year, when I needed to upgrade to > a larger drive, I used it and it worked fine. I bought a new drive (of > course of larger size... different manufacturer too), put it into a > drive enclosure, plugged that new drive into my USB port, and ran dd to > copy the entirety of hda to hdb. Shutting down the machine, I swapped > the hard drives and booted with the new drive and-- viola!-- new bigger > drive with everything running just like on the old drive. I didn't have > to reconfigure anything; even the networking worked on the new drive > without touching anything. The only thing I did on the new drive was to > create a new partition from all the extra new hd space I had. Indeed, > this is a multi-boot machine and all OSs on it copied over just fine. > In addition, all my linux partitions are encrypted, and all that copied > over perfectly as well. > > One tip: Use dd's smallest block size (BS). I did this copy using dd > several times, starting with 4k, then 2k block sizes and the new disk > had problems when I tried to use it. IIRC, I had to rachet down to 256 > to get a working drive. And this took eight or ten hours to copy an 80G > drive. Hmmm.... Using dump & restore (or tar or rsync or cpio, etc.) would likely be a lot faster. Esp. if the disk is not 100% full. Remember, dd will copy even the unused free blocks (which is a total waste of time). And dump & restore will likely use a more optimal block size, which will copy the data faster as well... > > Another tip: in your BIOS the parameter for the hard drive should > probably be Auto-Detect if your source and destination drives aren't > identical. That's generally the default anyway. > > Final tip (I think): For me, my machine A and machine B were the same > machine... so of course the hardware was absolutely identical. Using dd > might not work if the hardware on A and B are too different from one > another. > > > hth, > ken > > -- Robert Heller -- 978-544-6933 / heller at deepsoft.com Deepwoods Software -- http://www.deepsoft.com/ () ascii ribbon campaign -- against html e-mail /\ www.asciiribbon.org -- against proprietary attachments