How to prove that a restore will work

The way I test my dd backups is to restore them to another disk of identical size.

I test it on a new boot disk, if works , backup is good if not work, I still have original boot disk to continue testing.

Quote from doglover

To gderf and raulfg3:

Thanks. So clarifying, you restore to another hard drive (mounted internally or externally, I suppose it doesn't matter), and then replace your current hard drive with the restored one and see if you're back to the same place?

And do you perform this just once and then assume it will always work, or do this repeatedl?y (surely not with every backup, that would be too much work)

And you leave the newly restored test disk in there, don't put the old one back?

In a way seems like might as well just clone the second disk in one step, but I get it, is different than performing full/differential/incremental backups all the time.

Thanks

IMF

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I make automated dd backups of my OMV system disk nightly. To test, every six weeks or so, I restore the most recent backup to another disk, swap that disk with my boot drive, and reboot. If it boots and seems to behave properly, the backup is considered good. I then remove the test restore disk and replace with with the original boot disk.

Quote from gderf

I make automated dd backups of my OMV system disk nightly.

This automation is interesting.

Could you share the dd command or the script you use to do this?

And also, what size will the backup be, compared to the size of the boot disk? Is it 100% of it or is it compressed and how?

Quote from TheFax

This automation is interesting.

Could you share the dd command or the script you use to do this?

And also, what size will the backup be, compared to the size of the boot disk? Is it 100% of it or is it compressed and how?

Here is the script I use. The resulting dd image is the same size as the boot disk. I do not compress it.

#!/bin/bash

# Script to make dd image of system drive.

now=$(date +"%Y.%m.%d.%H.%M.%S")

file="omv-7-$now.dd.img"

cd /srv/mergerfs/backups/omv-backup-imgs # Change this to the location where you want the backup images stored.

#By USB socket position

dd if=/dev/disk/by-path/pci-0000:00:1d.0-usb-0:1.3:1.0-scsi-0:0:0:0 of=$file bs=1M status=progress #Change if= to the device of your OMV system disk.

# Prune backups older than 14 days.

find /srv/mergerfs/backups/omv-backup-imgs/*.img -mtime +14 -exec rm -rf {} \;