How to backup UFEI, and BIOS, partitions?

[spflanze]

I have a working Ubuntu 22.04 installation on a RAIDed encrypted ZFS file system. The procedure I followed can be downloaded from:
https://www.mediafire.com/file/2w8mdb96tbzslub/Ubuntu_22.04_Root_on_ZFS_Encryption.odt/file
This procedure is a customized version of rlaager's at:
https://openzfs.github.io/openzfs-docs/Getting%20Started/Ubuntu/Ubuntu%2022.04%20Root%20on%20ZFS.html

Before I migrate this installation to Pop!_OS I want to be able to easily restore the system to what it was before the Pop!_OS installation attempt. This is necessary because my prior experience is that this installation is a risky thing to do, and it can make the computer unbootable. The Ubuntu installation procedure requires a lot of time, and effort, that I seek to protect.

The snapshot procedure I am about to do is:

# Snapshot the Pools
zfs snapshot bpool/BOOT@snap_boot
zfs snapshot rpool/ROOT@snap_root
zfs snapshot rpool/USERDATA@snap_userdata
zfs snapshot hpool/HOME@snap_home

# Verify the snapshots are created:
zfs list -t snapshot | grep  "@snap"

My concern now is about how to backup the UEFI, and BIOS, partitions. What is the best way to do that? How necessary is it to back up these two parttiions to protect against damage a failed Pop!_OS installation attempt might do?

[m-ueberall]

Depending on whether the partitions are mounted and only contain files, I either use tar or dd along with gpg to encrypt and archive their contents as far as zfs send is not an option. IMHO, being able to restore the contents of these partitions using a recent backup in case of need is easier/faster than to recreate them. (Also, the resulting archives don't need much space at all.)

[IvanVolosyuk]

Nice idea with 'dd'. I wonder if there is a way to copy over a partition image file just the changed blocks, so that I could use snapshots for the disk image with a minimal overhead. [update] It looks like I can 'dd' the partition's device to a temporary file and then 'rsync --inplace' to the destination image :) [update] Sorry for the conversation with myself, but it looks like rsync --inplace will still rewrite full file: $ rsync -av --inplace /var/tmp/uefi-backup.img /archive/replica/boot/ $ zfs list -t snapshot archive/replica/boot NAME USED AVAIL REFER MOUNTPOINT ***@***.*** 107M - 107M - ***@***.*** 127M - 128M - Back to the drawing table or just screw this and accept wasted 100M space. Is there a tool which will reliably rewrite just changed bytes on the destination?

[bghira]

try rsync -c switch so it checksums data.

[IvanVolosyuk]

What I read in documentation tells me that --checksum is a per-file
checksum, but not a block-level checksum, thus doesn't help in this case. I
wonder if I can just write a simple .c program which compares and writes
bytes with the specified record-size boundary.

I hacked something really quick :)
https://github.com/IvanVolosyuk/inplace

[IvanVolosyuk]

It looks like I can 'dd' the partition's device to a temporary file and then 'rsync --inplace' to the destination image :) On Wed, Aug 31, 2022 at 11:29 AM Ivan Volosyuk ***@***.***> wrote:

…

Nice idea with 'dd'. I wonder if there is a way to copy over a partition image file just the changed blocks, so that I could use snapshots for the disk image with a minimal overhead. On Tue, Aug 30, 2022 at 10:01 PM Markus Ueberall ***@***.***> wrote: > Depending on whether the partitions are mounted and only contain files, I > either use tar or dd along with gpg to encrypt and archive their > contents as far as zfs send is not an option. IMHO, being able to > restore the contents of these partitions using a recent backup in case of > need is easier/faster than to recreate them. (Also, the resulting archives > don't need much space at all.) > > — > Reply to this email directly, view it on GitHub > <#13786 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/ABXQ6HJ3IFKHRZH47YFZWFDV3XZXZANCNFSM57B2CCBQ> > . > You are receiving this because you are subscribed to this thread.Message > ID: ***@***.***> >