Best practice for mounting a partition to use with timeshift for multiple users

Question

I am setting up a multi-user laptop for my wife, with me as an admin user in addition to her account. This is to wean her off windoze, so must be bomb-proof. Hence I want to set up timeshift, which I've not used before.

I'm not clear what permission etc are needed for the backup volume, and usually fail the first 3 or 4 times to get them right when I try to wing it. I have a spare 30 G FAT partition on the SSD that I'd like to use the backup volume.

I would guess that I need to edit /etc/fstab to mount the partition, perhaps to /mnt/backup, each time the system boots, in order that timeshift can find it. Is this correct? Are there any reasons for using different mount point roots like /media or /opt that I've seen suggested?

What permissions and ownership would I need for the mount point?

Answer 1

First, better to use another disk(other than system disk) for saving your backup.

Second, as you mention you should add to /etc/fstab file in the format:

sudo nano /etc/fstab

and add the line:

/dev/sdXX  /mounting-point  vfat defaults,umask=000 0 0

Note that mounting point could be any directory of your choice

Answer 2

• /opt is for installing software from a tarball. Often used to install more versions of a software (like mysql: you can use mysql8 from the repository and the use /opt/ to install mysql5.5, mysql5.6 so you can test different versions against your database.
• /media is for removable devices. Hard disks, USB sticks.
• /mnt used to be for internal devices but we nowadays prefer a custom directory in /

Permissions: set owner to your user, and create a custom group. Then add wife's user to the group. Commands:

sudo groupadd {newgroup}
sudo usermod -a -G {newgroup} $USER
sudo usermod -a -G {newgroup} {wife's_username}
sudo chown -R $USER:{newgroup} /{mountpoint}/

Change all the text using {} to what you want.

So this creates a new group (1), add your user (2) and your username your wife uses to that group (3). And the last line (4) sets permissions to your user and the group you both use.

You can use the group permissions to restrict actions (like make it impossible to delete files).

And then use Maythux method to add it to /etc/fstab