Getting Rsnapshot permissions right

Question

I've used rsync for years to keep a backup copy of my /home/User1 (Client1) on my Server1 (in a folder /mnt/Server1/Backup). These are not production machines. This folder is mounted on Client1 with NFS at boot in the /mnt/Server1/Backup folder (so /mnt/Server1/Backup on Server1 is mounted with NFS on Client1 in /mnt/Server1/Backup).

On both machines, /mnt/Server1/Backup belongs to User1/Group1 with permissions 770.

I installed rsnapshot on Client1 with the intention of getting it to backup on a daily basis in the folder (/mnt/Server1/Backup). User1 already exists on Client1 and Server1 and can SSH with keys and no password.

I've added the following to /etc/rsnapshot.conf:

##############################
### SNAPSHOT ROOT DIRECTORY ##
##############################


snapshot_root   /mnt/Server1/Backup/

##############################
### BACKUP POINTS/ SCRIPTS ###
##############################

# LOCALHOST
backup /home/User1  Client/

When I launch "rsnapshot configtest" I get "Syntax OK".

When I run "rsnapshot -t alpha" I get the following:

[dom ott 14, 01:12 ][user1@client1:~]rsnapshot -t alpha
echo 23033 > /var/run/rsnapshot.pid 
mkdir -m 0755 -p /mnt/Server1/Backup/rsnapshot/alpha.0/ 
/usr/bin/rsync -a --delete --numeric-ids --relative --delete-excluded \
    /home/Client1/ /mnt/Server1/Backup/rsnapshot/alpha.0/Client1/ 
touch /mnt/Server1/Backup/rsnapshot/alpha.0/ 
[dom ott 14, 01:12 ][user1@client1:~]

It seems like all is fine. However, when I launch without option t I get the following:

[dom ott 14, 01:12 ][user1@client1:~]rsnapshot alpha
----------------------------------------------------------------------------
rsnapshot encountered an error! The program was invoked with these options:
/usr/bin/rsnapshot alpha 
----------------------------------------------------------------------------
ERROR: Could not write lockfile /var/run/rsnapshot.pid: Permission denied

rsnapshot is complaining because there are no sufficient permissions for it to write the PID on main filesystem of Client1.

I don't think I should be using sudo otherwise how do I create a cronjob without asking of password?

I could use an ad hoc debian user "backup" ... but how do I resolve the PID problem?

Answer 1

In actual fact the sudo option is not working itself because it says that it can't write on the /mnt/Server1/Backup folder

     [dom ott 14, 01:15 ][antonio@gaia:~]sudo rsnapshot alpha
     [sudo] password di User1: 
     ----------------------------------------------------------------------------
     rsnapshot encountered an error! The program was invoked with these options:
     /usr/bin/rsnapshot alpha 
     ----------------------------------------------------------------------------
     ERROR: Could not mkpath("/mnt/Server1/Backup/rsnapshot/alpha.0/", 0, 0755);

I have found a workaround. rsnapshot had an option to set where the PID file is written. I set it as such:

     lockfile   /mnt/Server1/Backup/rsnapshot

I've also assigned the backup group to the above folder. Finally, what I've also realised is that rsnapshot is not even using SSH because I have the remote folder mounted on Client1 via NFS.