moving datadir when copy-back fails when symlink

[JasperAlgra]

Hi @ShahriyarR,

I'll try to make a PR for this later when I have some time. As you might have noticed I'm starting to use your tool in production so I'm currently doing a bit of bughunting by usage.

My mysql datadir in production are symlinks. E.g. /var/lib/mysql points to a mountpoint. When using autoxtrabackup --prepare the copy-back step literally moves this symlink to the tmp_dir.
Example:

root@db4:/mnt/backup# ls -ltr
total 8288
drwx------ 2 root root   16384 Dec 13  2017 lost+found
drwxr-xr-x 2 root root    4096 May  9 10:01 et_events
-rwxr-xr-x 1 root root      98 Jun 18 11:49 backup_start.sh
drwxr-xr-x 4 root root    4096 Jun 20 11:33 backups
drwxr-xr-x 3 root root    4096 Jun 26 14:00 archive
lrwxrwxrwx 1 root root      17 Jun 27 15:23 tmp -> /mnt/flash/mysql/
-rw-r--r-- 1 root root 8449837 Jun 27 15:23 autoxtrabackup.log

In /etc/bck.conf :

tmpdir=/mnt/backup/tmp

For me it would also make sense to not-move the datadir before copying back. My datadir is rather large and can better be seen as lost. Would you like me to implement an '--do-not-move-datadir' flag or so? Or a setting in bck.conf ?

Cheers,

Jasper

edit: other part of the symlink problem I just found out: copy-back creates a new dir in /var/lib/mysql. So the restore get written to my / drive. Which isn't a good idea in my case. probably a rm -rf /var/lib/mysql/* would be better instead of removing and recreating this dir.

[JasperAlgra]

edit2: the second problem is 'solved' by changing the datadir (from /var/lib/mysql to my /mnt/whatever/mysql ) in the bck.conf.
But the move to tmp when copying-back should still be optional (enabled by default). Do you agree?

[ShahriyarR]

Hi @JasperAlgra,
I was waiting for years to have somebody bughunting this tool and adopting to the needs of production :)
So please continue to find some interesting things.

I agree on this that when copying-back , moving to temp directory can be optional. Currently I can't remember if tmpdir has other usage beside this.
Having option for this is not a good idea, instead please make it optional in config, change code based on this and maybe you can even add some doc info on this 👍

[ShahriyarR]

@JasperAlgra are you still interested on this? :)

[JasperAlgra]

@ShahriyarR yes I am.. was a bit busy with work and now gone for holidays until end of aug. When I've got some spare time in sept I'll have a go at it!

[ShahriyarR]

@JasperAlgra Great news.
Have a nice holiday 👍