Linux Tips and Tricks Start / Stop /Restart BIND DNS Server Introduction For testing purposes I am using Univention with bind9. The greater goal is to use AD/SAMBA from Univention. After testing for a couple of weeks suddenly some DNS addresses do not get resolved. The same problems occurred on Zentyal. So far I couldn't find a reason for this misbehavior. However, a restart of the bind9 service seems to patch the problem. Debian based Linux Start the service service bind9 start Stop the service service bind9 stop Restart the service service bind9 restart Reload the service This will become necessary of a configuration file is changed. service bind9 reload Check status service bind9 status Fedora based Linux Start the service systemctl start named Stop the service systemctl stop named Restart the service systemctl restart named Check status systemctl status named   Install network scanner on Archlinux Install the drivers with pamac run the commandline: sudo brsaneconfig4 -a name=Brother model=MFC-9330CDW ip=192.168.1.108 check if it is working scanimage -L device `brother4:net1;dev0' is a Brother Brother MFC-9330CDW device `v4l:/dev/video2' is a Noname Logitech BRIO virtual device device `v4l:/dev/video0' is a Noname Logitech BRIO virtual devi   Install xrdp on Fedora 42 How to Set Up XRDP on Fedora 42 XFCE Follow these steps for a reliable and quick XRDP setup with XFCE on Fedora 42: Install XRDP and XFCE (if not already installed) sudo dnf install xrdp xorgxrdp   2. Enable and Start XRDP Service sudo systemctl enable --now xrdp   3. Configure the Firewall open Port 3389 for rdp 4. Set Up the XFCE Session for XRDP Create a file named .Xclients in your home directory with the following content:  echo "xfce4-session" > ~/.Xclients echo "xfce4-session" > ~/.Xclients chmod +x ~/.Xclients 6. Restart XRDP Services sudo systemctl restart xrdp sudo systemctl restart xrdp-sesman   7. Connect via RDP Use Devolutions RDM or any RDP client. Enter your Fedora machine's IP address and credentials.   Summary Table Step Command/Action Install XRDP sudo dnf install xrdp xorgxrdp Enable & start service sudo systemctl enable --now xrdp Firewall open port sudo firewall-cmd --permanent --add-port=3389/tcp; sudo firewall-cmd --reload Configure session echo "xfce4-session" > ~/.Xclients; chmod +x ~/.Xclients (Optional) SELinux fix sudo chcon --type=bin_t /usr/sbin/xrdp* Restart XRDP sudo systemctl restart xrdp xrdp-sesman This setup gives you a fast, graphical remote desktop on Fedora XFCE with minimal hassle.   Install send mail service on Fedora Overview This guide explains how to set up authenticated email sending from the command line on Fedora using msmtp (a lightweight SMTP client) and s-nail (a mailx-compatible mail utility). This method is ideal for scripts and system notifications in environments where only authenticated SMTP is allowed. 1. Install Required Packages sudo dnf install -y msmtp s-nail 2. Configure msmtp Copy the example configuration (optional): sudo cp /usr/share/doc/msmtp/msmtprc-system.example /etc/msmtprc Edit /etc/msmtprc and adjust to your SMTP provider: sudo nano /etc/msmtprc Example configuration: defaults auth on tls on tls_trust_file /etc/ssl/certs/ca-bundle.crt logfile /var/log/msmtp.log account default host mail.hosting.de port 587 from admin@simmy.org user admin@simmy.org password Set permissions to protect your password: sudo chmod 600 /etc/msmtprc 3. Configure s-nail to Use msmtp Add the following line to /etc/s-nail.rc or your ~/.mailrc : set mta=/usr/bin/msmtp 4. Send a Test Email echo "This is the body" | mail -s "Test Subject" recipient@example.com If the command returns no errors, the mail was sent successfully. Check /var/log/msmtp.log for troubleshooting if needed. 5. Notes If you receive an error like "Authenticated user is not permitted to override sender address" , ensure the from address in /etc/msmtprc matches the authenticated SMTP user, or configure your SMTP provider to allow the desired sender address. For use in scripts (e.g., backup notifications), simply use the mail command as shown above. References Sending e-mails via mailbox.org with msmtp on Fedora Fedora Docs: Mail Servers Fedora Forum: Sending mail with the (mailx) command Install send mail service on Debian Overview This guide explains how to set up authenticated email sending from the command line on Debian-based systems (including Proxmox Backup Server) using msmtp (a lightweight SMTP client) and s-nail (a mailx-compatible utility). This is ideal for system notifications, backup/email scripts, and environments with DMARC/SPF filtering where authenticated sending is required. 1. Install Required Packages apt update apt install -y msmtp s-nail 2. Configure msmtp Create/Edit the global configuration file: nano /etc/msmtprc Example /etc/msmtprc : defaults auth on tls on tls_trust_file /etc/ssl/certs/ca-certificates.crt logfile /var/log/msmtp.log syslog LOG_MAIL account default host mail.hosting.de port 587 from admin@simmy.org user admin@simmy.org password Important:  "from" and "user" should match your authenticated email address for DMARC/SPF.   Example 2 /etc/msmtprc syslog LOG_MAIL defaults auth on tls off tls_trust_file /etc/ssl/certs/ca-certificates.crt logfile /var/log/msmtp.log account ucs-backup host ucs-backup.simmy.ch port 25 from pbs01@simmy.ch account default : ucs-backup Use only plain ASCII spaces (no tabs or Unicode spaces). Set strict permissions: chmod 600 /etc/msmtprc 3. Configure s-nail or mailx to use msmtp Add the following line to your /etc/s-nail.rc (system-wide) or ~/.mailrc (per user): set mta=/usr/bin/msmtp 4. Send a Test Email Use the mail command to test sending: echo "This is the body" | mail -s "Test Subject" recipient@example.com On success, no output is shown. Check /var/log/msmtp.log or /var/log/mail.log (if syslog is enabled) for debug info if not delivered. 5. Troubleshooting If mail arrives in Junk/Spam, create a filter at your destination mailbox to whitelist the sender or move to Inbox. If you see an error like “ account default was already Install xrdp on Fedora Xfce Overview This document describes how to install and configure the XRDP server on Fedora 43 with the Xfce desktop environment so that Windows, macOS, and Guacamole clients can connect via RDP. Each Linux user who should be able to log in via XRDP needs their own startwm.sh to launch Xfce correctly.  Prerequisites Fedora 43 VM or physical host with the Xfce desktop environment installed (PRETTY_NAME="Fedora Linux 43 (Xfce)"). [web:14] Root or sudo access on the Fedora system. Network connectivity from RDP clients (Windows, macOS, Guacamole) to TCP port 3389 on the Fedora host. Install and Enable XRDP Install XRDP and its Xorg backend, then enable and start the service. Fedora 40/41 XRDP documentation uses the same pattern and works on Fedora 43. [web:21][web:17] sudo dnf install -y xrdp xorgxrdp sudo systemctl enable --now xrdp sudo systemctl status xrdp Open the Firewall for RDP If firewalld is running, open TCP port 3389 permanently and reload the firewall rules. [web:21][web:17] sudo firewall-cmd --permanent --add-port=3389/tcp sudo firewall-cmd --reload Create startwm.sh for Each User On Fedora, XRDP uses a per-user startup script named startwm.sh in the user's home directory to start the desktop session. Fedora's XRDP guide shows this pattern for multiple desktops; for Xfce the command is dbus-launch --exit-with-session /usr/bin/startxfce4 .  Repeat the following steps for each user account that should be able to log in via XRDP: # as the target user (not root) cat > ~/startwm.sh << 'EOF' #!/bin/sh export LANG=en_US.UTF-8 export LC_ALL=en_US.UTF-8 exec dbus-launch --exit-with-session /usr/bin/startxfce4 EOF chmod 755 ~/startwm.sh Explanation: dbus-launch --exit-with-session ensures a proper D-Bus session is created for Xfce, which is required for a fully functional desktop over XRDP. /usr/bin/startxfce4 starts the Xfce session. chmod 755 makes the script executable so XRDP can run it at login. Optional: Global /etc/xrdp/startwm.sh If you want a single configuration for all users, you can copy the same script to /etc/xrdp/startwm.sh so XRDP uses it globally. This approach is also referenced in XRDP discussions about custom session commands. sudo cp /home//startwm.sh /etc/xrdp/startwm.sh sudo chmod 755 /etc/xrdp/startwm.sh sudo systemctl restart xrdp Replace with a real user name when copying from an existing script. SELinux Considerations (Optional) On some Fedora installations, SELinux can interfere with XRDP. Recent XRDP-on-Fedora guides use chcon to assign the bin_t type to XRDP binaries if SELinux denials occur. [web:17] sudo chcon --type=bin_t /usr/sbin/xrdp sudo chcon --type=bin_t /usr/sbin/xrdp-sesman sudo systemctl restart xrdp Testing with a Native RDP Client Test XRDP with a standard RDP client before integrating with Guacamole. Fedora XRDP documentation uses Windows Remote Desktop as the reference client. [web:21] From a Windows machine, open Remote Desktop Connection ( mstsc.exe ). Enter the Fedora host name or IP (for example fedora-xfce.example.local ) and connect. [web:21] Log in using a Fedora user that has a ~/startwm.sh configured. Verify that an Xfce desktop session appears and is usable. Using XRDP from Guacamole Once XRDP and Xfce are working locally, Guacamole can connect using the RDP protocol. The key is to match the security mode and certificate options so that negotiation succeeds. Setting Value Protocol RDP Hostname IP Address Port 3389 Username ${GUAC_USERNAME} Password ${GUAC_PASSWORD} Security Mode TLS Ignore server certificate enable Summary Install XRDP and Xorg backend with dnf install -y xrdp xorgxrdp , then enable the service. Open the firewall for TCP port 3389 if firewalld is running. Create a per-user ~/startwm.sh containing dbus-launch --exit-with-session /usr/bin/startxfce4 and make it executable. Optionally, place the same script at /etc/xrdp/startwm.sh for a global configuration. Verify RDP access with a native client (e.g., Windows mstsc), then configure an RDP connection in Guacamole pointing at the Fedora 43 XRDP server.  Add a user to the sudoers group on Debian 13 usermod -aG sudo master How to Verify NFS export Check NFS exports on nas05.simmy.ch from the Linux: sudo showmount -e nas05.simmy.ch