[CentOS] Anything Like Solaris' Live Upgrade?

[xrx]

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 
upgrade.


-xrx