We've got about 200 existing servers running CentOS/RHEL 5.6 and all new servers are being provisioned using CentOS/RHEL 6.1. So that everything is consistent we need to upgrade the servers running CentOS/RHEL 5.6. I've searched the CentOS wiki, the Red Hat site, and the internet looking for something official on upgrading/migrating from CentOS/RHEL 5.x to CentOS/RHEL 6.x. There's got to be a way other than having 2 times hardware.
Any ideas???
Thanks, Gene Poole
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On Tue, 10 Jan 2012 13:55:05 -0500 Gene Poole wrote:
We've got about 200 existing servers running CentOS/RHEL 5.6 and all new servers are being provisioned using CentOS/RHEL 6.1. So that everything is consistent we need to upgrade the servers running CentOS/RHEL 5.6. I've searched the CentOS wiki, the Red Hat site, and the internet looking for something official on upgrading/migrating from CentOS/RHEL 5.x to CentOS/RHEL 6.x. There's got to be a way other than having 2 times hardware.
Backup your data/configurations, reformat, re-install your data/configurations.
There is no other "official way" to change from v5 to v6.
Gene Poole wrote:
We've got about 200 existing servers running CentOS/RHEL 5.6 and all new servers are being provisioned using CentOS/RHEL 6.1. So that everything is consistent we need to upgrade the servers running CentOS/RHEL 5.6. I've searched the CentOS wiki, the Red Hat site, and the internet looking for something official on upgrading/migrating from CentOS/RHEL 5.x to CentOS/RHEL 6.x. There's got to be a way other than having 2 times hardware.
Any ideas???
What we do is build one, then create /boot/new and /new on the next server, rsync over to them, then mkdir /boot/old and /old, and (using zsh with modules loaded) mv * old, mv old/lost+found ., mv old/new/* ., make sure a few things are correct (for example, ifcfg-eth*, /etc/ssh/), and sync, then reboot. All your other stuff is fine....
mark
On Tue, Jan 10, 2012 at 1:35 PM, m.roth@5-cent.us wrote:
We've got about 200 existing servers running CentOS/RHEL 5.6 and all new servers are being provisioned using CentOS/RHEL 6.1. So that everything is consistent we need to upgrade the servers running CentOS/RHEL 5.6. I've searched the CentOS wiki, the Red Hat site, and the internet looking for something official on upgrading/migrating from CentOS/RHEL 5.x to CentOS/RHEL 6.x. There's got to be a way other than having 2 times hardware.
Any ideas???
What we do is build one, then create /boot/new and /new on the next server, rsync over to them, then mkdir /boot/old and /old, and (using zsh with modules loaded) mv * old, mv old/lost+found ., mv old/new/* ., make sure a few things are correct (for example, ifcfg-eth*, /etc/ssh/), and sync, then reboot. All your other stuff is fine....
Have you looked at http://rear.sourceforge.net/ (and in EPEL) as a potential backup/clone/rollout mechanism? It seems like something that might suit your sensibilities, but I'm not sure what kind of contortions you would need to do to boot into its recovery image remotely. For anyone too lazy to look, it builds a bootable iso containing your own current system's tools to re-install itself, recreating the filesystem (LVM/raid/partitions) and dropping in a backup that can be included or separate. It is intended for mostly automated restores back onto the same system but I think it can be abused for cloning and there is a point where you can adjust the filesystem layout.
Les Mikesell wrote:
On Tue, Jan 10, 2012 at 1:35 PM, m.roth@5-cent.us wrote:
We've got about 200 existing servers running CentOS/RHEL 5.6 and all new servers are being provisioned using CentOS/RHEL 6.1. So that everything is consistent we need to upgrade the servers running CentOS/RHEL 5.6.
<snip>
Any ideas???
What we do is build one, then create /boot/new and /new on the next server, rsync over to them, then mkdir /boot/old and /old, and (using zsh with modules loaded) mv * old, mv old/lost+found ., mv old/new/* ., make sure a few things are correct (for example, ifcfg-eth*, /etc/ssh/), and sync, then reboot. All your other stuff is fine....
Have you looked at http://rear.sourceforge.net/ (and in EPEL) as a potential backup/clone/rollout mechanism? It seems like something
<snip> The one difference with the method we use is that you *don't* have to format /, and so anything you have under it is still safe. We normally have a few directories that are local, and so need to be saved (web, a temp that everyone can use that is guaranteed *not* to go away, etc).
It's also pretty quick: you don't affect the running system while you're rsyncing over, so then the rotation takes long enough to issue the few commands, check grub and fstab, and reboot.
mark
On Tue, Jan 10, 2012 at 3:35 PM, m.roth@5-cent.us wrote:
What we do is build one, then create /boot/new and /new on the next server, rsync over to them, then mkdir /boot/old and /old, and (using zsh with modules loaded) mv * old, mv old/lost+found ., mv old/new/* ., make sure a few things are correct (for example, ifcfg-eth*, /etc/ssh/), and sync, then reboot. All your other stuff is fine....
Have you looked at http://rear.sourceforge.net/ (and in EPEL) as a potential backup/clone/rollout mechanism? It seems like something
<snip> The one difference with the method we use is that you *don't* have to format /, and so anything you have under it is still safe. We normally have a few directories that are local, and so need to be saved (web, a temp that everyone can use that is guaranteed *not* to go away, etc).
But that also means you don't get to re-arrange your filesystem layout to set up a bigger /boot, change filesystem types, or fix something you've learned could be better in the years of running the previous version.
On 01/10/2012 12:55 PM, Gene Poole wrote:
We've got about 200 existing servers running CentOS/RHEL 5.6 and all new servers are being provisioned using CentOS/RHEL 6.1. So that everything is consistent we need to upgrade the servers running CentOS/RHEL 5.6. I've searched the CentOS wiki, the Red Hat site, and the internet looking for something official on upgrading/migrating from CentOS/RHEL 5.x to CentOS/RHEL 6.x. There's got to be a way other than having 2 times hardware.
Any ideas???
Note, it does not take 2x the hardware ... you only need 1 extra machine to convert 1 server at a time from 5.x to 6.x and when you get done, use that do the next one. You can do more than one on a machine with VMs as well (or as suggested, backup, format and bring on data, reconfigure)
You CAN (unsupported :D) also use a 6.x disc and run an upgrade over top the old machine. (It should offer that as an option for the install). But RH does not recommend or support upgrades done that way if using RHEL, so use at your own risk. Also please understand that things are not going to "just work" after an upgrade from CentOS 5.x to 6.x. For example, if you have php based websites using php-5.1.6-x in CentOS-5, you are likely going to have issues running them on php-5.3.x in CentOS-6.
The bottom line is that CentOS provides 7 years of support, but moving between major versions requires that you reconfigure everything. You can still get support for CentOS-5.x through 31 Mar 2014, so you have time before you need to move those 5.x servers to 6.x.
I'm trying to configure an old 64-bit desktop machine as a client for a CentOS server. The client must have no modifiable storage at all so my options seem to be: 1) Stateless network boot 2) Live DVD
I've been looking at the latter route, does anyone know if there is a convenient hook so that the live dvd will automatically download and execute a file during bootstrapping? I need to have some state, but held on the server. If there are any instructions for hacking the CentOS live dvd, please point me at them.
I'd prefer not to go for a complete stateless network boot, the server will be booted in a number of configurations and it would mean reconfiguring xCAT or similar on each set of disks. Just to be even more awkward, there is no external network connection to the server, which will be running a 64-bit variant.
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Rushton Martin wrote:
I'm trying to configure an old 64-bit desktop machine as a client for a CentOS server. The client must have no modifiable storage at all so my options seem to be:
- Stateless network boot
- Live DVD
I've been looking at the latter route, does anyone know if there is a convenient hook so that the live dvd will automatically download and execute a file during bootstrapping? I need to have some state, but held on the server. If there are any instructions for hacking the CentOS live dvd, please point me at them.
Not CentOS, but perhaps you might be interested in LPS http://www.spi.dod.mil/lipose.htm
No mounted storage at all, and built by a team from the US DoD, who *ought* to be paranoid enough for you. I've put it on a USB key, and have been saying for a month or so I need to try it (this would be for work, where I *have* to use a PIV "smart card" to get in from outside).
mark
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