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The script takes the drives as arguments:
$ pwd
/usr/lib/systemd/system
$ cat drive_backup.service
[Unit]
Description=backup fdisk + e2image
Wants=drive_backup.timer
[Service]
Type=oneshot
ExecStart=/usr/bin/backup_meta_data.sh /dev/sdc1 /dev/sdb1
[Install]
WantedBy=multi-user.target
Set to run at 3:40am every day, but probably could be once weekly really.
$ cat drive_backup.timer
[Unit]
Description=timer to run drive backup
Requires=drive_backup.service
[Timer]
Unit=drive_backup.service
OnCalendar=*-*-* 03:40:00
[Install]
WantedBy=timers.target
Should be fairly self-explanatory.
$ cat /usr/bin/backup_meta_data.sh
#!/bin/bash
working_dir=/home/st/drive_recovery/working
backup_dir=/home/st/drive_recovery
backup_date=$(date +%Y%m%d-%H%M)
mkdir -p $working_dir
sudo fdisk -x > $working_dir/$backup_date.fdisk
for var in "$@"
do
clean=$(echo $var | sed 's;/;-;g')
sudo e2image $var $working_dir/$backup_date.$clean
done
sudo 7z a $backup_dir/$backup_date.archive $working_dir/"$backup_date"*
sudo rm $working_dir/"$backup_date"*
Fantastic. I'm following!
May I point out that all a RAID1 does is sync the blocks between two drives. It won't protect against writing something dumb that would mess up the filesystem, it will just dutifully sync it.
You should be able to back up ext data from a filesystem on a RAID array, unless I'm confused about what e2image actually does. Are you trying to use it on the underlying drive devices by any chance? You have to point it at the RAID device on top of them, something like /dev/md1 rather than /dev/sda1.
This sounds like a good extra backup to have but don't let it lull you into a false sense of security. It may help recover from a very specific kind of mistake but the recovery may be very specific as well. It's not file backup.
Oh you're right it does work... well fuck knows what I was doing wrong before.
Yeah this is a backup in case I like, mv file to /dev/sda1 or something.
Not a backup of the files, but a backup of the structure.
I'm really curious as to why go to all this trouble instead of using a proper file level backup and restore solution.
instead of using a proper file level backup
Backups do not solve everything.
For example once I had a bad cable, and it did a kinda sneaking silent damage. Let's say 5 or 50 broken files every day. And only after some weeks I noticed some of them, and there was hardly a chance to identify them each day. And sometimes there was damage to the file system, too. It took a while find the root cause.
Today I use ZFS with redundancy and it does the recovery all by itself and my sleep is so much better :-)
Ok time to investigate ZFS
"Proper backups" imply that you have multiple backups and a backup strategy. That could mean, for instance, that you would do a full backup, then an incremental/differential backup each week and keep one backup for each month. A bad cable would cause you trouble, no doubt, but the impact would be lessened by having multiple backups points spread over months.
Redundancy is not backup. Read that again.
Redundancy is important for system resilience, but backup is crucial for continuity. Every filesystem is subject to bugs and ZFS is not special. Here's an article from a couple of days ago. If you're comfortable with no backups just because you have redundancy, more power to you. I wouldn't be.
I wasn't saying backups are useless or something.
I was saying there are situations that backups can't solve.
Sure, all the work you do between the moment of the filesystem failure and the last backup is gone. There's nothing that can be done to mitigate that fact, other that more frequent backups and/or a synchronized (mirror) system.
Backups are just a simple way to keep you from having to explain to your partner that you lost all the pictures and videos you took along the years.
For fun and learning. It's just another tool to go with file level backup.
And the backup for this is 40mb and really fast, but backing up files even when compressed would be hundreds of GB, maybe terabytes, and then you're paying for that amount of storage online somewhere, uploading for hours..
Picture this: you open and edit one of your documents and save it.
The filesystem promptly allocates some blocks and updates the inodes. Maybe the inode table changed, maybe not. Repeat for some other files. Now your "inode backup" has a completely different picture of what is going on on your disk. If you try to recover the disk using it, all you will achieve is further corruption of the filesystem.
e2image
There's a good reason for the 2 in the name.
Today we have ext4, and ZFS of course.
e2image - Save critical ext2/ext3/ext4 file system metadata to a file