[CentOS] Anything Like Solaris' Live Upgrade?

Mon Jan 28 18:05:32 UTC 2013
xrx <xrx-centos at xrx.me>

On 01/28/13 21:27, James A. Peltier wrote:
> ----- Original Message -----
> | Does anyone know of any sort of Linux utility that does something
> | like
> | what Solaris' Live Upgrade
> | (http://docs.oracle.com/cd/E19455-01/806-7933/index.html) does?
> |
> | In my past life as a Solaris sys-admin, I found this an extremely
> | useful
> | tool for upgrading and patching running systems, as well as for
> | maintaining redundant boot environments on separate system disks for
> | disaster situations.
> Nothing really until BTRFS comes of age.  I suppose you could snapshot your LVM volumes before performing the upgrade but to my knowledge there is nothing similar to Live Upgrade for CentOS
It does sound like you can do the roughly the same with LVM snapshots. 
Reading the introduction of the solaris document you linked; it seems as 
if the solaris upgrade is applied on say a snapshot; and then the system 
is rebooted into the upgraded environment; and if it works, great, if 
not you need a reboot back into the original state.

Wheras with CentOS 6; you take a snapshot of the root partition (easy as 
"lvcreate --snapshot --name RootSnapshot --size 2G /dev/VolGroup/Root"), 
and then do an upgrade with a reboot. If it works; you're set, if not, 
just revert back to the snapshot (lvconvert --merge 
VolGroup/RootSnapshot) and reboot; you'd be back to the state before the