[SOLVED] Prevent server software from writing to /mnt when SMB share is not mounted on Ubuntu Server

Superspeed500 · 09-13-2018, 09:11 AM

I have a Ubuntu 18.04 server that uses a combination of rsync and duplicity for backup purpose. Both are configured to sync the files to a SMB server with shell scripts run in a cronjob for the root user. The SMB server is mounted using data from /etc/fstab as /mnt/backup.

My SMB share, hosted on a qnap TS-431Xeu NAS, do sometimes go offline for updates or configuration updates. That causes rsync and duplicty to sync their files to the local disk under /mnt/backup resulting in serious problems with the server disk space.

So my question is: Is there a way to prevent all programs (or just rsync and duplicity) to write their files if the SMB share is not mounted at /mnt?

My fstab SMB entries:

Code:

# Connect SMB share for backup purpose
//<ip address>/Sikkerhetskopi\040(Linux)/ /mnt/backup  cifs    credentials=<removed for security>,iocharset=utf8 0 0
//<ip address>/Multimedia/Mediaserver/ /mnt/mediaserver cifs credentials=<removed for security>,iocharset=utf8 0 0

Thanks in advance

Guttorm · 09-13-2018, 09:34 AM

There's a command "mountpoint" that will tell you if something is mounted or not. In your backup script, you can add a check in the beginning of the script. Something like this:

Code:

if ! mountpoint -q /mnt/backup ; then 
  echo "/mnt/backup is not mounted - backup skipped!"
  exit
fi
rsync ...