On Fri, May 06, 2005 at 09:16:03PM +0200, wolf2k5 alleged: > Hi, > > I need to migrate a Linux system from a server to another one. > > I cannot reinstall the OS and applications on the new server and then > migrate the data from the old server, since that would require too > much time. > > In the past, to migrate a Linux system from a server to a new one with > HD of the same size, I shut down the servers, booted a Linux live CD > (Knoppix) on them and used 'dd' and 'netcat' to clone the system over > the network: that worked fine, but with two cons: > > - It is pretty slow, since it will copy over even blank data. > > - You cannot resize the partitions: if the new server has a bigger > disk, you cannot enlarge the original partition to use the additional > space. You should be able to fsck and use the filesystem's grow utility (resize2fs, resize_reiserfs, etc.) after you dd the partition. > Do you know any better way to clone the system over the network that > will fix the above problems? rsync instead of dd? That will just copy files. Be sure to use --sparse. My larger servers tend to have spare internal disks that are informal mirrors of the real boot disks. I manually rsync them from time-to-time so that I always have something relatively recent to boot. I've done OS upgrades by installing the new OS on a test box, and rsyncing from the test box to the server's spare disks and rebooting then just rebooting to the new disks. Obviously this is a very error-prone method because you need worry about boot partitions, boot loaders, device names, fstab, etc. > I think the commercial application Symantec Ghost can do it, but I am > looking for something free. > > It would be great if such tool supported PXE boot too. > > On a separate note, do you know how to boot Knoppix via PXE without > using the Knoppix Terminal Server (that requires an additional > machine)? > I already have a Linux host running TFTP/DHCP/NFS servers and use it > to perform Red Hat Enterprise Linux installations via PXE. > How do I configure it to perform Knoppix boots via PXE? I haven't found a way to boot an ISO image over the network. I can netboot linux and dos floppy images (dos floppies are useful to automate BIOS/firmware updates over the network). -- Garrick Staples, Linux/HPCC Administrator University of Southern California
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