automatic dump and restore over
Hi, I think I have a plan for upgrading a large number of computers over the network. I would really appreciate some help finding flaws in this idea. 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. 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? Thanks, Rickard. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: automatic dump and restore over
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 pgp0.pgp Description: PGP signature
Re: automatic dump and restore over
Thanks for all the good answers. Just one final question. Do you think it is at all possible to do this update without rebooting? It would save time but I assume that this is impossible. The reason I thinking of doing it this way is because I need to distribute the update on a bootable cd. I need a method that is as failsafe as it can be without any user-interaction (Except for turning the power switch). Thanks, Rickard. - Original Message - From: Matthew Seaman [EMAIL PROTECTED] To: Rickard Dahlstrand [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Sunday, January 11, 2004 1:51 PM Subject: Re: automatic dump and restore over 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 ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
