On 15/05/15 12:18, Carl Turney wrote:
Hi All,
BACKGROUND:
Am a single-system home-office user of Linux. Not a professional sysadmin. Running Linux Mint 17 Qiana, desktop, 64-bit Intel.
My "total system backup" scheme has been (for the last ~10 years) to run rsync (in a script, from / recursively), onto similarly-formatted/installed disks. Has worked perfectly over the years, on Fedora, Ubuntu, and Mint... as backups are essentially clones, and become new master disks in the event of crashes.
I'm definitely not a pro sysadmin either, but I tend to live dangerously. I think the crucial word here is "essentially". I presume your system is using the venerable MBR booting method which contains a direct reference to a spot on the disk where there is bootstrap code, and this ref. is set when grub2-install is run either implicitly or explicitly. When you copy the grub first-stage bootstrap binary to another disk it will not be in the same position on the disk - I think it is a disk not a partition reference that is used, so if you wish to change which is to to be the bootstrap that will run _its_ grub.cfg then you need to run grub2-install to configure what you want. Having a bootable USB stick with all your favourite things makes this easier. I find that the SanDisk Extreme 16G or larger gives the best performance here. I have lots of OS partitions spread around multiple disks and machines mostly on SSD, each exactly the same 15G size, and I back them up using dd to an external HD via eSATA-III to make an exact partition clone to a file. It only takes a few minutes each. The fun bit is when you put two clones on the one system - you need to change one of the UUIDs (tune2fs -U <>) and edit the UUID in the grub.cfg of the booting one to match. Btw - this implies that you clone the MBR to a file as well - every time that you make a change to the partition table or run grub2-install. You may find documentation at /usr/share/doc/grub2-tools/grub.html Be aware that it can be dated - it describes grub2-install as just a script, but I had a look and on my FC21 it is a full blown binary.