> On Mon, Feb 11, 2019 at 04:16:38PM +0100, Simon Matter via CentOS wrote: >> > 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! >> >> 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? > > 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? I'm not sure about the rescue mode in CentOS 7 but booting from external media will work for sure. Simon