Handle efficiently your nfs, samba shares even when it is offline.

0_samba_shares_offline.md

Mounting samba shares with this method, https://wiki.archlinux.org/index.php/fstab#Automount_with_systemd gave me some freeze when accessing samba shares when it has been disconnected. Using systemd timeouts does not help : https://bbs.archlinux.org/viewtopic.php?id=225973 .

As an alternative, using https://wiki.archlinux.org/index.php/NetworkManager#Network_services_with_NetworkManager_dispatcher gives some good results : no freeze when shares are offline.

For Samba configuration refer : https://www.tecmint.com/setup-samba-file-sharing-for-linux-windows-clients/

In order to be able to write on shared drives, either configure samba with create mask=0770 Force create mode=0770 or add it to fstab

//a4h-rpi-dev-remi.local/rpi_projects /mnt/partages/a4h/rpi-dev_projects cifs _netdev,noauto,credentials=/etc/samba/credentials/a4h/rpi-dev_projects,file_mode=0777,dir_mode=0777 0 0

fstab_share_entry

//a4h-rpi-dev-remi.local/rpi_projects /mnt/partages/a4h/rpi-dev_projects cifs _netdev,noauto,credentials=/etc/samba/credentials/a4h/rpi-dev_projects,file_mode=0777,dir_mode=0777                                    0  0
                                   0  0

mount_network_drives.sh

#!/bin/sh

echo "Executing wifi network shares (Network dispatcher script)"

# mounts defined in /etc/fstab
home_mounts=("/mnt/partages/home/partage" "/mnt/partages/home/openhab_configuration")
work_mounts=("/mnt/a4h-rpi-dev_projects")

function net_drive_mount
{
  nb_attempts=10 
  for mount_id in "${@}"
  do
    while [ $nb_attempts -gt 0 ]
    do 
      if mount $mount_id
      then
        echo "$mount_id successfully mounted"
        break 
      else
        echo "attempt $nb_attempts : could not mount $mount_id"
      fi 
      sleep 0.2 
      nb_attempts=$[$nb_attempts -1]
    done  
  done
}

function net_drive_umount
{
  for mount_id in "${@}"
  do
    echo $mount_id 
    if mount | grep "$mount_id" 
    then
      # umounting can take some time when drive is offline
      # but as soon umount is called, umount seems to be 
      # effective : access to previously mounted drives
      # are not freezed during some sec
      echo "umounting $mount_id in a background process"
      umount -l "$mount_id" &
    fi 
  done
}

if [ "$2" == 'down' ]; then
  # try to umount all shares 
  net_drive_umount "${work_mounts[@]}"
  net_drive_umount "${home_mounts[@]}"

elif [ "$2" == 'up' ]; then
    conn_name=$(iwgetid wlo1 -r)
    if [ -n "$conn_name" ] ; then
      if  [ "$conn_name" == "A4H_creativity_lab" ] ; then
        echo "at work : mount creativity lab network drives"
        net_drive_mount "${work_mounts[@]}"
        
      elif [ "$conn_name" == "Bbox-DCE7FB" ] ; then
        echo "at home :  mount network drives"
        net_drive_mount "${home_mounts[@]}"
      fi 
    else
      echo "could not get wireless connection name - may be connected over wired network"
    fi 
else
    echo "nothing to do for event $2"
fi
echo "End of wifi network shares (Network dispatcher script)"
exit 0