On 01/28/13 22:14, Tim Evans wrote: > On 01/28/2013 01:05 PM, xrx wrote: >> 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. > Thanks. You also need to manage the grub and fstab configurations to > allow the second boot environment to be visible, bootable, and mountable. > > Are you talking about CentOS? There is no need to change the fstab or grub; the upgrade gets applied on the main volume (where the OS can be upgraded on the fly without a reboot if it works out; or optionally with a reboot if you want to be extra sure). The snapshot is only there if the update goes bad; in which case you'd run the merge command to revert back to the original state. -xrx