[Info-vax] Somewhat levels up to not port outside VMS (letter from Wyoming)

[Scott Dorsey]

Neil Rieck  <n.rieck at sympatico.ca> wrote:
>First off, it would be nice to do a snapshot once a week just incase someon=
>e installs or upgrades something so we can go revert back. Perhaps its just=
> me but I have never been able to fully rollback CentOS-7 so any tips are d=
>efinitely welcome.

Try xfs.  The snapshotting isn't perfect, but you can do it, and it's already
supported under Centos.

>Secondly, I've got two HP platforms (DL385) running CentOS-7 with out any h=
>/w RAID or s/w mirroring. These systems are one drive away from failure so =
>receiving any tips on how to move the system disks to a slightly newer DL38=
>5 with h/w RAID would also be welcome.

Depends on what you want.  Might be easiest to reinstall the OS on the new
machine, then just dd or dump/restore everything from one machine to the 
other.  Of course, then you have to reinstall everything else that goes on
the OS disk, which may be problematic.  

If the drives are interchangeable, you can pull the drives out of one machine,
put them into the other machine, then boot and have an identical config.
Then it's just a matter of migrating to a raid on the same system.  But, to 
do this you need enough drive bays for both the raid and the original disks.

>Everyone reading this already knows that the Linux system disks are partiti=
>oned so migrating is a little harder. Well, I suppose I could always boot a=
> third disk in single user mode; create new partitions on the new RAID volu=
>me to match the old system disk; then copy the disk partition-by-partition.=
> I was just wondering if there is a less error-prone method.

If the drive is identical you can just dd the raw drive over to a new raw
drive.  The partition table and the grub stuff all comes along for free
although you'll need to install a new boot sector.

Don't you have Dawn Whiteside up there?  Pay her to do it.
--scott

-- 
"C'est un Nagra. C'est suisse, et tres, tres precis."