Adding a Pi Zero to the Pi menagerie

A Pi Zero

So I already have a Pi 4 4GB and 1GB. The 4GB Pi is where this web site is hosted along with our stash of TV shows and movies and as well as serving up the web site we use it to play our shows via VLC and a 4K HD TV. That all works very well and it just sits there and does its stuff. It’s visible to the internet on ports 443 for the web server and 22 for maintenance when I’m not at home. It has 1TB or storage attached.

The 1GB Pi is our file store – backups of our Windows systems, our digital photos, iTunes music, our movie and show collection, etc. It is also a MySQL server for various databases that I keep for community group stuff. This Pi isn’t visible to the internet at all and has about 5TB or storage attached all SSD.

Both the 1GB and the 4GB Pi’s are running 64 bit kernels although the 4GB Pi is 32bit userland. The 1GB Pi is fully 64 bit. They both boot from USB SSD devices.

Both of those Pi’s have Samba running and they share various directories. The whole setup works very, very well.

When I first got the 1GB Pi it was supposed to be a sort of development and test system for other stuff I’m working on. That scenario lasted only a short time, however.

So what to do about a test system ? A Pi Zero of course. It doesn’t matter what I wreck – I can just make another SD card if I mess up too badly. So I ordered one along with a power supply, a HDMI adapter and a plastic case.

After a small hiccup within about an hour or so I had it in its case with the 128 x 32 OLED Display  from Core Electronics attached and working.

The hiccup was born of not paying attention. I imaged the 64bit PoOS to the brand new SD card and spent a bit of time trying to work out why it wouldn’t boot. I should’ve read what the Pi Imager was telling me and used the correct version of PiOS. You can take it from me that a 32bit PiZero can’t use the 64bit OS. Idiot….

The longest parts were making the SD card from the latest correct download and updating it once I had it booted.

Pi Zero with plastic case and 128×32 display

First impressions ? Geeze it’s small and for such a small package it’s surprisingly capable – much more so than my 80’s IBM Thinkpad running OS/2 Warp.

Now that I’ve got my bascic configuration up and running I’ve taken a copy of the SD card using the handy built in utility so I’ve got a basic fallback position should I mess things up irretrievably.

Next step is to make a start on a python3 script to control the fans on the other two Pi’s then there’s a couple of other MySQL things that I want to do with the community group database and that’ll be followed by some HAM radio stuff that I’ve been looking at for a while now.

 

 

An even bigger small display

Adafruit 240×240 display

So after a bit of success with the previous two Adafruit displays I figured that I’d try their 240×240 display so I ordered one and given the current COVID-19 induced postal delays it eventually arrived.

I wasted no time in disabling the script that runs the 128×64 display and plugging in the new one.

Getting it working with a sample Adafruit script took no time at all so I now had to write another Python3 script to run the bigger display. I worked out roughly what I wanted to put on it and in which orientation. With a decent font size and by tweaking the height and width parameters in the script I found that I had eleven lines to play with.

As ever my Python3 skills are a bit Neanderthal so it took a while and was really, really messy to start with. But at least it worked.

Once I set to work putting a bit of doco in the script and cleaning it up a bit I only needed an hour or so to make it look a bit respectable, to me at least, and to have it still work. It’s here for your perusal if you so desire.

It even looks fairly neat apart from the fan wires that are not connected any more due to the display taking the 5V pins. I’ll have to work out a way of sourcing the 5V from somewhere else although the fans aren’t really needed – the Pi 4 4GB usually runs at less than 60 deg C even when playing HD videos with VLC.

Adafruit Mini Pi tft 1.3-240×240

What it displays

After a bit of messing around I have it displaying the date, the time, CPU temp, CPU and memory usage, disk usage, swap usage, uptime, boot time and three lines for button presses, etc. I’ll probably mess around with these lines and the button callbacks some time in the future.

Anyway another success with an Adafruit display. If you have a look at the script that drives it you’ll no doubt see that my Python3 skills are lacking and that I’ve probably gone about everything in the most inefficient way possible.

There are a few bits of the script that I found as code snippets and messed about with to get the results that I wanted, other bits are directly from Adafruit.

For my next trick I want to have a slideshow running and have the buttons set up in such a way that I can switch what I’ve got now to a slideshow and back again. I was think to have both buttons present a sort of menu so that I can Poweroff, Reboot or go with a slideshow. I have absolutely how I’m going to do it yet though.

Stand by for future developments. In the meantime, if you have any suggestions for the script(s) that I’ve already written please let me know.

 

 

 

 

 

 

 

A slightly bigger display

The Adafruit 128×64 OLED Bonnet for Raspberry Pi

So after getting the little display I decided to have a go with the Adafruit 128×64 OLED Bonnet for Raspberry Pi. After a bit of messing about this is what it looks like in operation

Adafruit 128×64 OLED Bonnet for Raspberry Pi

I’ve put eight lines of text on it and enabled a few of the buttons / joystick. The test is date, time, cpu temp, CPU and memory used percentages, root partition usage, swap usage, uptime and the boot time. The buttons thus far assigned are button 5 for reboot, button 6 for power off, joystick down is Samba restart and joystick up is Apache2 restart. It required a fair bit of messing around as well as learning a bit about GPIO pins and acting on the buttons.

Anyway here’s the Python3 script. It isn’t particularly well commented – the comments were more for my use while I was writing it. And nor is there any error checking. Python3 seems to do a pretty good job of that.

The next step

For my next trick I want to have a play with a Adafruit Mini PiTFT – 135×240 Color TFT Add-on for Raspberry Pi. I don’t know what I’ll display on it yet but I’m sure I’ll think of something.

I’m also tossing around the idea of having a play with the PiTFT Plus 320×240 2.8 TFT + Resistive Touchscreen

Because of all this messing around during the COVID-19 restrictions that we are living under here in Victoria, Australia I reckon I may have to get another Pi. Probably a 2GB Pi 4 this time – I already have a 4GB and a 1GB and I cant see a reason for forking out the extra cash for the 8GB iteration.

Of course another Pi means another SSD to boot from, another case and probably a fan shim. Hmmm. I can see the price of all this creeping well toward unaffordable already.

 

 

A neat little display

A four line system monitor

Whilst doing a bit of idle web surfing I stumbled across this little gizmo and thought that it would provide me with a few hours of amusement so I went ahead and ordered one. After it arrived it sat on my desk for a few days while we shot off to Omeo for a bit of a break for a few days.

When we got back I installed it and started playing. Fortunately Adafruit have a sample python script which I was able to massage to come up with this.

Raspberry Pi 4 4GB with a heatsink case and four line display

As you can see it displays the date, time, CPU temp and memory and CPU usage.

I’ve already got USB booting happening so it boots from a 1TB Seagate USB 3.0 SSD which is just two partitions – “/boot” and “/”. That works well too.

The python script

This was, or is, my first ever python script. I’m adept at Perl, COBOL, Fortran, etc. so I was able to work out a simple script with only minimal messing around. It’s a good thing that Adafruit have some detailed instructions which include a python script to get it working. A bit of modifying / rewriting the Adafruit script and I had it displaying what I wanted.

So, without further ado here’s here’s the Python3 script which I was going to embed here but WordPress is wilfully destroying the indentation.  A quick look will reveal that there is no error handling whatsoever. I haven’t learnt how to do that yet so that’ll be introduced on another day. There’s also almost no commenting either.

 

What now

Well now that I’ve got this working and working well I thought that I’d get one of these which has buttons and is a bigger. The little one that I have now will go onto my other P1 4 (1GB) which is used for storage and as a test bed for this site. It’s also booting from USB and is also running Pi OS 64bit which seems to me to be nice and stable.

The bigger display will allow more lines of text but I don’t know what I’ll put there yet. It also has a couple of buttons and a joystick. I can use the buttons for things like “sudo reboot” or “sudo poweroff” or something.

Stand by for future developments.

 

 

 

USB Boot

Why ?

Why USB boot ? Well for a start I’m a tinkerer who just can’t leave things alone. Secondly I’ve had an SD card fail and didn’t want to go down that path again – maybe I should’ve got better cards ? And thirdly I’ve always, rightly or wrongly, regarded the SD card boot scenario a bit clumsy.

I got rid of some of the clumsiness by moving the root partition to a 1TB Toshiba X1 portable SSD. This was easily done and was a great success. I still had a bit of SD clumsiness though which I wanted to get rid of.

Then along came the announcement of USB booting and for once in my life I didn’t leap into the deep end with the first BETA. I waited until the BETA was elevated to STABLE and then leapt into the deep end.

What follows is what I did to get it working.

First steps

The first thing to do was to get my hands on another portable SSD.  This time it was a Seagate 1TB portable SSD. Not cheap but hey, you can’t let money stand in the way of a bit of tinkering, can you ?

The second thing to do was to make sure that my existing installation was completely up to date by doing “sudo apt update” followed by “sudo apt full-upgrade”. Because I hadn’t done this for a while there were about sixty packages updated. While I was at it I had a look to see what I could get rid of and removed a couple of packages that I didn’t require.

Next on the list was to update the boot loader and get it configured. That’s the bit the seemed a bit daunting at the start.

Update the bootloader

I was a bit worried about this bit but only because I had no real backout plan if it all went badly. I needn’t have worried.

First up I had a look at “/lib/firmware/raspberrypi/bootloader/” and saw that there was a “stable” directory and saw that there was “pieeprom-2020-06-15.bin” which was what I was after according to this topic on the Raspberry Pi forum.

Because I have a second Pi that USB boots 64 bit Raspbian that I set up a couple of weeks ago I had already done a lot of reading about the configuration. The story of the second Pi is here.

Anyway I’m jumping the gun a bit here. Before updating the bootloader I downloaded the latest version of Raspberry Pi OS and using the Raspberry Pi Imager I set my Seagate portable SSD up with it. While that was happening I got the bootloader updated and configured. Easily done in a few steps.

I needed a configuration so I used the one from my 64 bit Pi :-

[all]
BOOT_UART=0
WAKE_ON_GPIO=1
POWER_OFF_ON_HALT=0
DHCP_TIMEOUT=45000
DHCP_REQ_TIMEOUT=4000
TFTP_FILE_TIMEOUT=30000
ENABLE_SELF_UPDATE=1
DISABLE_HDMI=0
BOOT_ORDER=0xf41

I got this by doing vcgencmd bootloader_config > bootconf.txt on my 64 bit USB booting Pi. It was a simple matter to copy that to my non USB booting Pi.

Back to the 32 bit Pi and I did “rpi-eeprom-config –out pieeprom_new.bin –config bootconf.txt  /lib/firmware/raspberrypi/bootloader/stable/pieeprom-2020-06-15.bin”  which gave me a new bootloader called pieeprom_new.bin to install.

Installing the bootloader was my mental sticking point. Up to this point I had a working system with the root partition on an SSD and the /boot partition still on an SD card. Would it still boot after the new bootloader was installed ? I certainly hoped so!

Anyway I went ahead confident that I could roll it back to the old non USB booting model simply by installing the bootloader from the “critical” directory. Anyway I did a “sudo rpi-eeprom-update -d -f ./pieeprom_new.bin” followed by a reboot and it booted just fine. I did a “vcgencmd bootloader_version” and a “vcgenccmd bootloader_config” and was greeted by the new version and the new configutation. It had worked and my web server / samba / other stuff system worked as it it always did.

 

Making the new boot SSD

Now to the fun part.

Remember the SSD that I made with the latest Raspberry Pi OS ? Well now its time to shine has arrived.

I plugged it into the Pi and copied /boot/*.elf and /boot/*.dat to the boot partition of the SSD. I closed the Pi down (sudo poweroff and unplug the power) and unplugged the original SSD and the SD card leaving the new SSD plugged in. I plugged the power in and lo and behold it booted OK and I went through the whole setup process. That’s half the job done. The brand new SSD had the boot and root partitions and all was right with the world.

I powered off again and rebooted the original configuration – SD + SSD (Toshiba). The new Seagate was plugged in and I formatted the root partition “mkfs -t ext4 /dev/sdxx” and mounted the new empty, clean partition in /mnt. Then came “rsync -axv / /mnt” There’s about 700 GB in that partition so it was going to take a while so I went to bed.

One caveat here. If I plug both SSD’s into USB-3 ports it will fail at some point probably, I think, because it’s on the edge of the available power from a genuine Pi power supply. If I plug one of the SSD’s into a USB-2 port it’ll work OK so I did that which made it a lot slower.

It worked

The next morning, after a couple of cups of coffee, I had a look at what happened overnight. The “rsync” had completed without error.

At this point I needed to copy from the SD card config.txt and cmdline.txt to the new SSD so I did that. I also needed to edit cmdline.txt to make sure that the PARTUUID pointed to my new SSD. On the new SSD I needed to edit /etc/fstab to put in the new PARTUUID’s for the boot and root partitions.

At this point I was very hopeful but not certain that it would work out properly but I went ahead and powered the Pi down and removed the original SD and SSD and plugged the new SSD into a USB-3 port and plugged the power in. Success. Everything works OK. This web site works OK as does Samba and everything else.

The whole operation was a success. Apart from the “rsync” it only took about half an hour. Because of the sheer quantity of “stuff” the “rsync” was a lengthy affair.

The next step will be to update with Raspberry Pi OS 64bit when that becomes prime time. I’m sure that won’t be a simple upgrade like this ended up being.

Pi 4 USB Boot and 64bit Raspbian

Introduction

I have a perfectly working Raspberry Pi 4 1GB which is acting as a Samba server with a few TB of storage attached which we use to store our nightly backups, scanned and digital photos and a bunch of other stuff which is important to us. It was working well and didn’t need fixing or otherwise messing with at all.

Then the USB boot and 64 bit beta’s became available so I just had to try them out, didn’t I ?

Suffice to say that it all worked perfectly and now my Samba server has booted from a USB device and is running the new 64 bit beta OS.

Here’s how I did it.

USB Boot

All I did was to follow the instructions here. Please have a read of this most excellent doco before you do anything else.

Another thing that must be done before you start is to make sure that the proposed USB boot device works properly with your Pi. I have a couple here that work perfectly with Windows and iPad but just will not be recognised by Raspbian Buster.

Make a new SD card. I downloaded the image from the Raspberry Pi download page and put it on a new SD card using the Raspberry Pi Imager – Your mileage may vary if you use Balena Etcher or something else.

The next step is to put your image burner to use again and burn the image to the USB boot device that you will wish to boot from and put it to one side.

Boot from the new SD card that you just created and go through the setup process. Then do a “sudo apt update” followed by a “sudo apt full upgrade”. I rebooted the Pi at this stage. Next comes the first of the fun parts.

As root, edit /etc/default/rpi-eeprom-update and select BETA releases. I found that you need to have “beta” in lower case. Then do “sudo rpi-eeprom-update -d -f /lib/firmware/raspberrypi/bootloader/beta/pieeprom-2020-05-15.bin”

Do “rpi-update” and copy *.elf and *.dat from /boot to the boot partition on the USB device that you’ve put to one side. Do a “sudo poweroff” and remove the SD card. Reconnect the power and it should boot from the USB device if you’ve done it right.

I followed the instructions here and they proved to be invaluable. The whole operation worked properly the first time I tried it so follow the instructions in the doco and you’ll probably not go wrong. If it all goes wrong just go back to the beginning and start over.

I can still boot from my original SD card if I need to so I have a fallback if I need it.

64 bit Raspbian

While I was making my Pi boot from a USB device, Raspberry announced a 64 bit beta of Raspbian Buster. Of course, I just had to try it out in conjunction with USB booting.

I downloaded the 64 bit Buster image and using the Raspberry Pi Imager I prepared a USB SSD with it.

I did a “sudo poweroff” and swapped the USB devices over and plugged it back in. Imagine my surprise when it booted without any issues. I did the setup and I had a Pi with 64bit Raspbian Buster booted from a USB device. Not an SD card in sight..

Next was to get it updated and Samba installed. Again it went without a hitch. To make life a bit easier I copied fstab, /etc/dhcpcd.conf and smb.conf from my original SD card. “fstab” was not a direct replacement. I just edited the fstab (on the new 64 bit device) and put the mounts for my storage in it. The other two files were direct replacements though. Rebooted and it looks exactly the same as it did with the original SD card.

And it all came together

Well, at the end of the processes it all works perfectly. I’m sure that there will be more issues to overcome as the USB boot and 64 bit Raspbian move out of “beta” and into “production”

In the grand scheme of things it gained me exactly nothing apart from a bit more knowledge about the workings of the Pi and Raspbian.

I’m not touching the Pi that this web site is on – it’s a web server, a media player and store, a database server, etc. This Pi I regard as being critical and all precautions are taken to keep it up and running. I take nightly incremental backups and weekly full backups of the whole system including MariaDB database backups.

Sooner or later though, I’m going to have to bite the bullet and fully upgrade this Pi – a prospect that I’m most certainly not looking forward to.

LAMP+WordPress

Seeing as I managed to get USB boot and 64 bit Raspbian working so easily I figured that I may as well go for broke and get a duplicate of this web site happening.

First up I installed Apache, MariaDB, php and php-mysql. That was all very easy as it usually is.

Next up was to make a database for WordPress and create the relevant user. No problems here either. Then I installed the latest copy of WordPress and configured it. Again, no problems.

The bit that I expected the most trouble from was getting a copy of the WordPress installation and data across from this site to the new Pi configuration. All I did was to install the duplicator plugin on both sites and export it from this site and install it on the test Pi.

So now as well as Samba, I have LAMP+WordPress working. It’s hardly the definitive test, I know, but it’s an encouraging preview for when 64 bit Raspbian comes out of beta and into the real word.

Another good thing to come out of this exercise is that I may have discovered a path towards upgrading when USB boot and the 64 bit OS comes into prime time.

The importance of backups

What happens when it all goes pear shape

A couple of days ago we had a small power “glitch” here. Apart from the microwave clock going back to zero and the TV going off the Raspberry Pi that this site runs on went down.

When I powered it back up I found that my WordPress site was devoid of content. Further panic stricken investigation revealed that the “wp_posts” table in the database had a corrupt index. After much gnashing of teeth, googling and experimenting (after taking a copy of course) I was unable to fix the problem.

What to do ? Well I bit the bullet and restored a backup I’d take about a week earlier using the “Updraft” plugin. Apart from losing a week’s worth of content all was well. And this is where good fortune stepped in.

During the couple of hours before the power glitch I’d been messing around putting an “RSS Subscribe” in the side bar and testing it on my iPhone. It proved to work well too so on a whim I had a look at the RSS on my phone and it had handily retained all of the content from this site so I was able to e-mail it to myself. From there it was a simple matter to copy and paste the content to the recreated posts. Whew.

The only thing that I lost was about a week’s worth of stats from “WP Statistics” plugin. I can live with that but I’d rather that I didn’t have to though.

OK so I was lucky

So, this time I was lucky ! I only lost a very minimal amount of stuff. The stats and the configuration for Google AdSense.

As a retired large system administrator I know full well the importance of good backups. I wasn’t taking them on a regular basis because “what could possibly go wrong”.

I’m now using a Linux backup package for the whole Pi and I’ve scheduled a backup of WordPress once a day. As well as that I’m taking an Updraft backup right atfer I do anything of any note to WordPress or the system as a whole.

Raspberry Pi and TVheadend

How to turn a standard definition TV into a HD TV

What you’ll need.

A Raspberry Pi 4 and a Raspberry Pi DVB TV Hat or a DVB-T/T2+C+FM+DAB dongle. You’ll also need a TV with HDMI input to plug the whole shooting match into.

The first thing to do is to get Raspbian installed and updated to the current standard. I didn’t pay any attention to secure passwords, etc. as this Pi is not going to be connected to the internet directly. Access is only going to be from the home network.

The next thing to do is to plug in either the Pi TV Hat

TV Hat

or your dongle.

DVB-T/T2/C+FM+DAB dongle

 

Next step is to install TVHeadend – “sudo apt install tvheadend” will get the job done. Before you start on the next step a very important step is to plug the antenna into either your TV Hat or dongle.

 

 

Getting it configured

When you are installing TVHeadend be sure that you select a username and a password combination that’s dead easy to remember.

When you’ve got it installed break out your trusty web browser and go to https://x.x.x.x:9981. The x.x.x.x could be localhost if you are doing it from either a TV or monitor connected to the Pi or it could be another system connected to your home network. In either case you’ll be prompted to supply the username and password that you specified during the TVheadend installation. You’ll be presented with a configuration page which is easy to work through. There’s a wealth of info at tvheadend.org which will see you right.

At this stage you should have an Electronic Programme Guide (EPG) visible in your browser and now’s the time to test it to see if it all works. If at this point if you have no success go back to the TVheadend configuration. It took me a few iterations to get a handle on how it works. Once you can see the EPG you’re home and hosed.

Be aware though, you really do need a decent TV antenna to get it working. I don’t think the receivers in either the dongle or the Pi TV hat are very sensitive. Another problem that I ran into was getting the correct region to scan. I started out using “au-other” which was incorrect. When I used “au-Melbourne” it worked as advertised. Like all of my other issues, it was my faulty configuration.

Testing and Job Done

At this point yould be able to select a programme in your browser. You now may have problems getting your browser to support the stream from TVheadend. Don’t worry, salvation is at hand in the form of VLC which can play network streams.

Just install it on the system that uses your old, slow, standard definition TV. Open it up and go to “media -> Network Stream” and enter the followung “https://username:password@x.x.x.x:9981/playlist/channels.m3u” where “x.x.x.x” is the network address of the system that uses your TV as the display. Or any other system on your local home network. You may have to select “View -> Playlist” from the menu to get the playlist. From there you just select the channel that you want. Double click on it and hit full screen mode.

Be aware though, you’ll need a high speed network connection between the system with TVheadend and the system with the TV attached. Of course if the system with TVheadend is directly connected to the TV then this is redundant.

With this setup I can take my tablet down the back yard to the BBQ area and kick back with the cricket and a glass of wine or two. I can’t watch HD TV there though – I’m only just in range of my 2.4GHz wifi which doesn’t quite cut it but hey, it does the job.

Sit back with a glass of your favourite and watch the programme of your choice in HD whilst congratulating yourself on a job well done.

More LAMP and WordPress

Well there have been some “developments” since I got LAMP and WordPress going.

I’ve tried and abandoned an e-mail server.

I’ve decided that 500GB of storage isn’t enough given our collection of “stuff” – you know, pictures, movies, TV series (Medici is good), music, etc. so I got my grubby fingers on a couple of 2TB Sandisk Extreme SSD drives. Using the same procedure I used to move the /root partition from the SD to the 500gb SSD I moved the /root partition again to a 2TB SSD. I left it as a single, big partition and made a mount point for the second 2TB SSD and put that in fstab using PARTUUID. I moved the contents of our ancient NAS drive onto that. It makes a huge difference to have a share (Samba and NFS) on a 1Gb network connection rather than the old 100baseT connection.

We now have more than enough storage for our foreseeable needs and it’s fast too. I’ll have to get a four port, powered USB 3 hub though. Copying downloaded stuff over the network or via USB 2 is slooooow compared to USB 3.

Meanwhile the Pi 4 4GB keeps on rocking along.

Getting e-mail happening

So I had this brainwave and thought it’d be a good idea to set up a Pi as an e-mail server. After all, how hard could it be, there are hundreds of thousands of mail servers around the globe that work well. What could possibly go wrong ?

I started out trying to keep it simple. I’m pretty familiar with Sendmail but I figured that I’d go with something simple as I was only going to serve two users and Sendmail seemed a lot of overkill.

After a bit of searching Citadel seemed to fit well. I installed it and configured but there is no way I could get past a couple of errors not the least if which is “db:cursor still in progress on cdb 02: attempt to write during a r/o cursor”. I tried a completely fresh install of Raspbian Buster with a brand new install of Citadel. Still no dice. Searched for more comprehensive doco but, again, to no avail. I reckon I just about wore out the search engines looking for a solution but still no illumination. I even tried downloading the source and buildin it from scratch. The same olf “db:cursor still in progress…” error persisted.

Scratch Citadel which is a pity really as I reckon it’d be the bees knees for a simple and small e-mail server.

On to Dovecot and Postfix. I had a few issues but by carefully following the documentation on Postfix.org I had it all up and running. In the beginning I had a lot of trouble getting “saslauthd” to do the authentication and I spent a goodish amount of time trying to treat the symptoms without success. At this point I decided to get rid of postfix and dovecot and start again from a new install of both. The big difference this time was that I folloed the docs on postfix.org to the letter. Surprise, surprise it all worked as it should.

After years and years of telling people to RTFM I didn’t.Once I did RTFM I proved my own point yet again.

Now came the hard part. DNS records. I use a dynamic DNS which has served me very well thus far. Setting up the MX record was very easy but I discovered I needed a PTR (for reverse lookups) and this is where the gremlins started to creep in. I needed a static address. No problem just ask my ISP, right ? Easily doable, for another ten bucks a month. Sign the static IP over to the dynamic DNS provider so that they can use it for all DNS records. ISP says – “oh no we can’t do that”. Luckily my dynamic DNS provider has a facility that can easily get around that particular scenario.

Now that it all works, I’m happy and am quite willing to advocate for the Postfix / Dovecot sulution. It’s a lot easier to configure than Sendmail. The configuration files are well commented and make sense, unlike Sendmail.

If you’re considering setting up your own mail server first check that you can get a PTR DNS record. If you can’t look for another solution. If you can, RTFM and pay attention to the details and recommendations.

Just for fun and games on our internal network I set up a DNS complete with MX and PTR records and with the internal e-mail system configured to insist on reverse lookups it worked perfectly with no errors. Of course this was only with two Pi’s, two PC’s and two windows tablets. I’ve got rid of it all now I know how to make it work and that there’s no point with an uncooperative ISP.