How to best backup my Gentoo install?

[G3nt00]

Hi,

already getting a bit cozy running Gentoo! Everyone is so helpful and I have achieved much in a short period of time! But, that makes me think of how I should back this all up.

Is there a "preferred" way to backup a whole system? I need nothing fancy, perhaps just a bootable USB which can create a compressed image or two of the disk, and some way to write it back if I ever should need that.

Thanks

[linux_os2]

Have a look at CloneZilla.
It even can clone a windoze.

https://clonezilla.org/

[szatox]

What are your constraints?
Some good tools for a single system are rsync and tar, and if you have lvm you can use snapshots to improve consistency.
For multiple systems you might consider a dedicated solution; there like 50 options in app-backup category. Bacula/bareos, backuppc, borg, duplicity (i think this one can actually do local backups), rsnapshot...

Whatever solution, make sure your backups run automatically and on schedule: if your backup requires any manual actions, you have no backup.

[G3nt00]

[G3nt00]

[Hu]

[G3nt00]

[sabayonino]

Hi

One of my partition(s) backup solution is

[G3nt00]

[szatox]

[G3nt00]

[szatox]

HDD offers cheap space. SSD offers cheap IO.
Backup tends to use a lot of space and relatively little IO, so HDD is the way to go. Also, backup is mostly sequential write, which allows HDD spin up to its full speed. My cheap 7200rpm drives move around 180MBps in this scenario, which is definitely not bad.

Reliability is something you get from having at least 2 copies, no matter what medium you use. Whether or not it is necessary, depends on your scale of operations, skill, clumsiness, how risk averse you are, and what the cost of failure would be... Even with a single backup losing data requires a few things to go wrong at the same time, so my (unpopular) opinion is that 1 backup copy is good enough for personal use.
Note: backup is by definition a short-term storage. If you want to archive something, possibly deleting it from the source device to release space on "hot" storage, you definitely need 2 copies. If your livelihood depends on it, your backup should be cloned too.

[G3nt00]

[NeddySeagoon]

G3nt00,

What you need to back up depends on how fast you need to recover.

1. If you use a SSD, do not backup/restore empty space. Backing up is a read, restoring is a write, even if its empty.
2. Backing up a file system that is in use will give you corrupted open files. Hence, backups need to be run on an unmounted filesystem. Snapshots are good.
3. You need /home, as all your user data is there.
4. The content of /etc/portage and /var/lib/portage/world is enough to rebuild your system.

You only need more if you don't have time for a reinstall.

EFI users have everything in filesystems, except for the efivars.

BIOS users need to preserve regions outside of filesystems too.
BIOS users need to copy/restore (with dd) the space before the first partition as grub stage1 and stage1.5 are there.
BIOS users with GPT need the MBR and the grub_bios partition (again with dd)

Users with an encrypted install will get unencrypted filesysnem backups, as the filesystem(s) have to be decrypted and mounted to copy the files.
They can be encrypted on the backup. It all depends on your paranoia level.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[pietinger]

Maybe I misunderstand you, but it seems to me, you want a full disk backup to be able to get back your system easily ... maybe also in a case where your harddisk is not broken, but you want have the original system as you had before. If this is true the best solution is to work with snapshots, as @szatox already suggested. If you want a backup solution you must be aware of this:

1. Dont try to backup /dev /proc /run and /sys. Maybe exclude /tmp also. Check IF and WHAT is mounted in /mnt ! Maybe exclude it also. Be aware it could be possible that /boot is NOT mounted (if you use in your /etc/fstab the "noauto" option).
2. The safest solution for a complete system backup is: Boot from another system (CD-ROM; USB-stick). Then you can be sure no process is working with an open file. If you dont like that, then you an do a backup from a running system IF you close all used applications - especially database applications (if you must backup a running database you will find extra commands from your DBM to do so).
3. Think: WHAT is necessary to get all data back to a NEW harddisk:
a) Booting a minimal Linux system (e.g. with our Gentoo minimal install CD)
b) Partition and format the HD
c) Copy back all data
Now the question how many time you have for (a) and (b). It is possible to automate it ... but you must test this BEFORE you may need it.

You can do all jobs with rsync ... I do it also ... BUT ... I am using a "graphical frontend" for rsync: luckybackup ! Luckybackup tells you also IF some files have been changed while the backup is running...

What many people dont know: rsync has the option "--dry-run" which does what it says: It tells you what rsync WOULD do ... AND this option is also in luckybackup; its called: simulation. With this you can test/check if your backup job does what you want (without doing it for real). BTW: luckybackup is so easy to configure that even I was able to do a backup via SSH from one machine to another.

[reckor]

To make it simple, what I do is:

1) Clonezilla for image backup - to boot from it, etc. It works pretty well, but you will need to re-run the image creation from time to time, let's say every 6mo?
2) FreeFlieSync - for me the easiest and best solution for backing up your /home (it works for copying the whole disk too, but I use for personal files). This one has NO gentoo ebuild, so up to you to install from their Linux version ( I did and happy user ).

Another option is to run the following (you can also automate it if you wish):
rsync -axvP /home/<user name> <backup dir> ---> to backup.
rsync -axvP <backup dir>/<user name> /home/ --> to restore.

This is copy incremental files preserving the rights and numeric-ownerships (which is important as you may know).

3) mkstage4 - just in case I create a Stage 4 tarball from time to time as @sabayonino mentioned.

Good luck

[Zucca]

[G3nt00]

Thanks guys!

I will try out Proxmox Backup server first and see if that could be what I want/need. Unfortunately I had a disk failure, on top of my Gentoo seriously malfunctioning, so this will have to wait until after a Gentoo reinstall - Yes, I know, all can be fixed, but there is just too much going on right now to dive into everything. That time will come too though. And yes, I am almost sure I was the cause of it failing (disk not though).

[NeddySeagoon]

G3nt00,

Cheap horrible SATA cables fail more often than drives. That can have all the hallmarks of a drive failure, until you look at

[G3nt00]

[figueroa]

EDITS on 2/9/2024: (I learned the hard way of the need to include leading slashes (/) to the entries in the excludes file, in particular for the entry to exclude the contents of the root directory "sys." In the original by having the entry "sys/*" all file paths matching sys/* anywhere in the file system were found and then excluded from the archive. My assumption had been that the excludes were relative to the current directory only, and I was wrong. My new, improved excludes file has been substituted below; tested and found to be working as intended.)

I think more users should ask this question. Prevents alligator tears.

Every few days, at night, root's crontab runs my very simple stage4 shell script to create a full backup of my full operating system. These currently run about 4.7 GB and takes about 22 minutes on my main desktop. The script is in two parts, the tar script, and the file with exclusions.

[G3nt00]

[Section_8]

If you a set on making a filesystem image, and the filesystem is ext2/3/4, you might look at e2image (provided by sys-fs/e2fsprogs) instead of dd. It avoids copying the unused space.

[G3nt00]

[Goverp]

Another one for ext2/3/4 systems, to add to the fun, is app-arch/dump. Old but, for me anyway, good. You need to send the output to a file (-f) rather than the default tape, of course.
_________________
Greybeard