On Sun, Jan 11, 2004 at 12:00:12PM +0100, Rickard Dahlstrand wrote: > All the servers is installed with one partition for /, one for /var/. When I do the > initial install I move the /etc to /var/etc and synlink /etc to point at /var/etc. > This should make the / partition exactly the same on all the servers.
If you move /etc like this, you'll make the machines so treated unbootable. There's critical stuff in /etc that has to be in the root partition for the boot process to be able to find it. > On the reference server (where I do all the upgrades) I then use dump to create a > file from the / partition. This file is the zipped and moved to my laptop from > installation on all the other servers. > > The laptop is then connected to the same network as the server that needs upgrading. > The laptop is running DHCP, TFTP and NFS services. > > All servers are set to boot using PXE and once I reboot it the server boots an image > from the laptop containing a picobsd dist with a modified startup script. > > This script automatically mounts the hard drive on the server and a directory on the > laptop containing the dump-file from the reference server. Then it uses restore to > write the dump-file over the / partition on the server. > > After the upgrade is complete I reboot the server without the DHCP server active and > the server should boot using the new / partition. > > Can this work? I have read that dump/restore is the best solution for backing up > disks. Could there be any problems using restore on a partition already allocated? It strikes me as a lot more complicated than the recommended method, which is to designate one machine as a 'build box', where you build all of the OS and kernels you need. You then NFS export /usr/src and /usr/obj and mount them on the machine you want to update. Then you can use 'make installkernel', 'make installworld' and 'mergemaster' to do the update. Possibly with a few other steps here and there -- for full instructions start with: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/small-lan.html However, if you decide to stick with your first idea, then I'd make a few changes: i) Copy the contents of /etc to your /var as a backup. Leave the original /etc in place on the root partition. If you're going to be doing this sort of thing regularly, then you can set up a cron(8) job: the net/rsync port will let you do the copies very efficiently. ii) Before you rewrite your root partition, you should run newfs(8) on it to blank it. restore(8) can overwrite a populated partition, but it works best given an empty filesystem. iii) After you've restored your example root partition, copy back the contents of /etc. Note that this will wipe out any updates to files within /etc which came as part of the upgrade. mergemaster(8) will help you fix things up, or you can be selective about what contents of /etc you actually keep backed up -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK
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