Due to lacking driver support for newer hardware I have been missing hardware monitoring on my home server for more than 4 years now, having access to only hard disks temperatures.
Now the time has come to upgrade the good ol’ machine to a new hardware configuration – and of course the new hardware is also unsupported in even the latest CentOS kernels.
The Raspberry Pi is very handy for fun projects, and sometimes these projects require running specific events (like playing a sound) on startup or shutdown, or even in both instances – for an interactive machine that reacts to user input and presence, for example.
Sounds on startup and shutdown can also be used as a means of confirming those specific actions taking place – startup is complete and shutdown is taking place (and will complete in a very short while).
Proxy virtual hosts are very handy when you need to publicly access a tertiary system on your local network and you only have one IP address to use but there’s a master web server already configured.
If that server is running Apache, adding a proxy vhost to pass outside requests to the correct LAN system is as simple as adding a new virtual host to the configuration.
Sometimes, due to connectivity issues (or even NextCloud bugs), files may end up in a locked state on the server. This means they can no longer be modified in any way, not even deleted.
By default dd doesn’t display any status information while performing its operation. Newer versions include a status parameter which can be used to activate progress output.
Many Raspberry PI projects are used headless (with no display device attached or if a display device exists, it’s not connected to the default HDMI or analog outputs).
In these instances it’s time consuming to connect the PI to a monitor and keyboard just to configure remote SSH access and wireless connection details (and in rare occasions it may even not be possible).
Luckily, the good folk developing Raspbian implemented shortcuts and workarounds that allow things to be pre-configured even before booting the PI.
After migrating a RAID volume to new disks it’s handy to keep a full partition backup around.
For this we can use partclone, a handy smart backup utility which is capable of recognizing multiple filesystem structures and then save only used data.
In case the hard disk itself is taking too long to respond, some operations will fail and can cause the controller (software or hardware) to drop the disk out of the RAID.
Even when no RAID is used, the hard disk itself can still spend too much time retrying a (failing) read, causing unwanted delays and possible further damage.
To alleviate this, you can try to use a feature called TLER (Time Limited Error Recovery) or CCTL (Command Completion Time Limit).
Installing an operating system remotely comes handy when you don’t want to spend all the time required for the install process next to the physical machine or want to give someone else access to perform the procedure.
CentOS is one of the OSes which supports remote installation using the VNC protocol.
By default SSHd will terminate an ongoing connection if there was no traffic (incoming or outgoing) for a while.
If you usually leave remote sessions running for long amounts of time and hate the unexpected disconnects, this can be changed by enabling the keep-alive feature on the server directly so it applies to all remote sessions regardless of client used.
CentOS is a conservative distribution giving you the most stability and security, at the expense of newer features like the latest PHP release.
Fortunately there are ways around for getting a newer PHP by using one of the several repositories out there providing updated packages. My personal choice for this task is Remi’s Repository.
Since OPNsense is more vanilla FreeBSD it is a lot simpler to install additional FreeBSD software on it than on pfSense.
One piece of additional software that can be useful, especially for monitoring and statistics purposes, is munin.
