how to restore an entire UEFI system from an rsync backup

K.H.Braun · 05-03-2024, 10:01 AM

Hi Folks
I have just trashed my Slackware system. It refuses to let me login using known good passwords

I do have rsync backups of of the 3 filesystems that comprise this installation of Slackware64-14.0.
These 3 filesystems are mounted on /boot/efi, / and /usr.

SO:

Since the slackware on my box box is tentoesbellyupdead How can I
restore the entire system from the 3 backups?

Thanks in advance for your help!

pan64 · 05-03-2024, 10:18 AM

assuming you destroyed only / (root filesystem) boot another OS and restore it.
Would be nice to know what's going on, what's happening.

Another way can be to reinstall slackware and overwrite it from the backup, but again, would be nice to know what should be restored.

rizitis · 05-03-2024, 11:02 AM

something like this:
access the filesystems and perform the restoration without interference from the potentially corrupted system.
Mount the drives containing your backups. Since you have backups of the /boot/efi, /, and /usr filesystems, you'll need to mount these

Code:

mkdir /mnt/backup_efi
mkdir /mnt/backup_root
mkdir /mnt/backup_usr

mount /dev/sdX1 /mnt/backup_efi    # Replace sdX1 with the appropriate partition for /boot/efi
mount /dev/sdX2 /mnt/backup_root   # Replace sdX2 with the appropriate partition for /
mount /dev/sdX3 /mnt/backup_usr

Code:

rsync -av /mnt/backup_efi/* /boot/efi/
rsync -av /mnt/backup_root/* /
rsync -av /mnt/backup_usr/* /usr/

Update /etc/fstab

business_kid · 05-03-2024, 12:13 PM

Quote:

Originally Posted by K.H.Braun

Hi Folks
I have just trashed my Slackware system. It refuses to let me login using known good passwords

I do have rsync backups ............

That funny familiar feeling of thrashing your system that so many of us have had...

It doesn't follow that just because you can't log in, every byte of your system is destroyed. So in light of this joke

Quote:

Originally Posted by Billy Connolly

Who discovered you could get milk from cows, and what did he think he was doing at the time?

What was going on at the time? Are you sure everything has to be redone? What did you think you were doing at the time?

rokytnji · 05-03-2024, 04:00 PM

Gee. No df -h posted in this thread.

No sudo parted -l either?

Maybe all the OP did was improper shutdown which corrupted the file system.

If so. Running a live gparted session and unmounting drives and doing checks on partitions Is how I fix that on my boxes.

business_kid probably hit the nail on the head.

mrsam · 05-04-2024, 03:22 PM

The fact that this is apparently an UEFI-based system adds more excitement to this situation.

Boot a live ISO image. Any Linux distro live image would work, but if one insists on Slackware, a brief Google search finds https://download.liveslak.org/ Follow the live image's instructions to create a bootable USB stick with the live image. Shove in the USB stick. Go into your hardware BIOS and do whatever needs to be done to boot from the USB stick.

With this out of the way, after booting the live image you should be able to mount your USB stick with your backups, run fdisk to repartition your hard drive, mkfs the partitions, and rsync-restore them. Important: the /boot/efi partition must be a vfat partition, not ext4. Additionally, since this was, apparently, an EFI-based system you must use fdisk to create a GPT, and not legacy BIOS partitions.

Once everything has been rsync-ed over, you'll need to head back into your system's BIOS set up and figure out how to configure its EFI loader to boot from the rsynced system. It's fairly likely that playing with fdisk ended up generating new GPT partition table, which would invalidate any previous EFI configuration.

In desparate times one might choose to forget about EFI, and create a legacy BIOS partition. Note that this path will require mounting the hard disk partition, chroot-ing into them, and then running grub-install to install the grub bootloader (I forget the equivalent incantation for LILO).

colorpurple21859 · 05-04-2024, 03:30 PM

IMHO, the problem is on / or /usr, leave the efi partition alone, attempt to fix the other two partitions.

wpeckham · 05-04-2024, 05:56 PM

And after he gets things working again perhaps learning how to do partition and device backups rather than just file backups. (BOTH together is far better than either one alone.)