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bare-metal backup before update--options?

Hi all!

I'm a "nervous nellie", I have not yet updated my 7.5 desktop to 7.6
because (1) it has an Nvidia card, and (2) I've heard of problems
upgrading on top of software RAID (using RAID1 with 2 drives).

I need to upgrade it to stay secure, and I want to do a bare-metal backup
first (so I can put it all back as it now is, in case it explodes in my
face), so I'm trying to figure out the safest way to do that. Here are
the choices as I see them, I'd appreciate comments/thoughts:

1. boot from live DVD and manually reassemble the RAID array (how
would I do that?)
2. degrade the array (with appropriate commands) so that it is running
on just one drive, then boot a live DVD and use dd to back up that drive.
3. Other choices you can suggest?

then after successfully getting a bare-metal backup, reboot it with the
full RAID array and run the update.

Thanks in advance!

Fred

Comments

Re: bare-metal backup before update--options?

By Johnny Hughes v... at 02/11/2019 - 11:16

To me the easiest method seems to:

- boot into rescue mode, not mounting any disks
- directly dd all complete disks to files on a USB disk or to a remote host
- reboot and update as usual

If anything fails you can again boot into rescue mode (maybe with the help
of USB/DVD/CD) and:

- recover all disks using dd from the backups made before
- reboot and be back on 7.5

Any reason why this shouldn't work?

Regards,
Simon

Re: bare-metal backup before update--options?

By fred smith at 02/11/2019 - 20:01

On Mon, Feb 11, 2019 at 04:16:38PM +0100, Simon Matter via CentOS wrote:
Thanks for the reply!

by rescue mode, do you mean (1) the "rescue" kernel in the boot menu?
Or (2) an option on one of the installer DVDs?

Wouldn't (1) boot from the existing drives and mount them?

Fred

Re: bare-metal backup before update--options?

By Johnny Hughes v... at 02/12/2019 - 05:39

I'm not sure about the rescue mode in CentOS 7 but booting from external
media will work for sure.

Simon

Re: bare-metal backup before update--options?

By Mike Burger at 02/11/2019 - 11:06

Hi, Fred,

On 2019-02-11 10:04, Fred Smith wrote:
I've been a big fan of Mondo Rescue. <a href="http://www.mondorescue.org/" title="http://www.mondorescue.org/">http://www.mondorescue.org/</a>