Home directories outside of '/home'

The snap daemon (snapd) looks for a user’s home directory ($HOME) under /home on the local filesystem. However, from snapd 2.59 onwards, the snap daemon can access an additional location using the homedirs system option:

sudo snap set system homedirs=<destination-directory>

This allows a snap’s user data to be stored in a user’s home location other under /home.

The following command will permit home directories to be accessible from /remote/users, for instance:

$ sudo snap set system homedirs=/remote/users

The new location needs to exist and be accessible, but it can be on a different filesystem or even mounted across a network. The original /home location remains valid but it is no longer a requirement that directories be stored there.

Once set, the homedirs system option can be retrieved with the snap get command:

$ sudo snap get system homedirs
/remote/users

The homedirs value can be cleared and restored to only /home with the snap unset command:

sudo snap unset system homedirs

Bind mount home directories

While the homedirs system option should work for the majority users, it’s still possible

In addition to the homedirs system option, it remains

However, it is possible to bind mount an alternative $HOME location to /home to allow other locations to be found by snapd. This process is outlined below.

A bind mount allows a mounted filesystem to be accessible from more than one location at the filesystem level. This is unlike a hard or symbolic link, for instance, which operate as special additional files that point to a destination.

There are two steps to bind mount a home directory to a different location:

1. the bind mount: create the mount point and run the mount command:

   $ sudo mkdir -p /home/$USER
   $ sudo mount --bind <original-home-location> /home/$USER
   

2. edit /etc/passwd: backup passwd and edit the home location for your user:

   $ cp /etc/passwd passwd.backup
   $ # sudo edit /etc/passwd with your favourite editor
   $ cat /etc/passwd | grep $USER
     ubuntu:x:1000:1000:ubuntu,,,:/home/ubuntu:/bin/bash
   

   The following awk command can be used to edit /etc/passwd (change OLD_HOME to your old home directory):

   $ awk -vold=$"OLD_HOME" -vnew=$"/home/$USER" -F: ' BEGIN {OFS = ":"} \
     {sub(old,new,$6);print}' /etc/passwd > passwd.new
   $ sudo cp passwd.new /etc/passwd
   

Log out and back in again, and snap will work from the freshly mounted home location. If you run into difficulties, copy the backup passwd file to /etc/passwd.

Last updated 6 months ago.