Linux Mint 19 on an HP EliteDesk 800 G1 Mini

I picked up a couple of these second-hand recently, to use in the observatory. They came with Windows 10 installed, but I don’t care about that. I want to run Linux Mint on them.

I tried a couple of times to install from my Mint 19 DVD, but just kept getting the error:

The 'grub-efi-amd64-signed' package failed to install into /target/

Something about UEFI seems to mess things up. It made no difference if I removed the Windows boot entry using efibootmgr from the live desktop, or even if I deleted the entire partition table from the disk. I always got the same error. It took me quite a while to find a solution. What finally worked was this:

Once the above error occurs, allow the install process to stop and then open a terminal window. In the window, use sudo to get a root shell (“sudo -s”). The first thing I needed to do was to edit /etc/hosts to add some of the hostnames that would be used later by apt-get. I don’t know if this is a problem specific to my setup or will generally be the case, but I added entries for packages.linuxmint.com, archive.ubuntu.com and security.ubuntu.com to the file, using another machine to look up the IP addresses (and just picking one where there were several). At the time of writing, I added:

208.77.20.11 packages.linuxmint.com
91.189.88.24 archive.ubuntu.com security.ubuntu.com

There’s a Canonical host used too, but I just ignored the errors about that in apt-get.

The next step is to run the following commands (all as root)

# mkdir -p /mnt/boot/efi
# mount /dev/sda2 /mnt
# mount /dev/sda1 /mnt/boot/efi
# for i in /dev /dev/pts /proc /sys; do mount -B $i /mnt$i; done
# chroot /mnt
# apt-get update
# apt-get install ubuntu-system-adjustments
# apt install --reinstall grub-efi-amd64-signed
# os-prober
# update-grub
# ^D

At that point I was able to restart the machine and it booted straight into Mint 19.

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Swimming, 9th August 2019

Had a bit of barney with Mrs Indignant Triathlete today, who wasn’t chuffed to be asked to move into the slower lane to allow my son and I to swim in the faster one. She claimed to be able to swim a 1’20s 100m freestyle (which is faster than I can do it), clearly intending to suggest that it was me who should be in the slow lane. Only she then proceeded to swim 1’20s 50s compared with mine of about 48s and my son’s of something like ten seconds faster than that. Even including my rest interval I was faster than her over 50m. Hey ho.

USRPT distance this year: 165,800m
Total distance this year: 206,700m

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Swimming, 8th August 2019

And another warm water day…

USRPT distance this year: 165,800m
Total distance this year: 204,900m

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Swimming, 6th August 2019

Same old, same old 🙁 I’m really looking forward to the pool temperature returning to normal.

USRPT distance this year: 165,800m
Total distance this year: 203,100m

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Building an observatory. Construction #80

I didn’t have a lot of time this evening, but took a monitor, keyboard and mouse down to the warm room, connected them and one of the pier computers up to the KVM switch and powered everything on.

All the hardware seems to work fine, despite the length (5m, from memory) of the HDMI and USB cables. I even managed to pick up a wifi signal from the house, but it wasn’t stable enough to use for any length of time. I think I was averaging about 10Mb/s over the wifi link, dropping down to 1Mb/s at times. It was like being in the 1980s 😀

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Swimming, 5th August 2019

The pool is still ridiculously warm, but I’m slowly adjusting to swimming in it. I’ve not returned to doing proper USRPT sessions yet though.

There is at least one positive for today though, in that I have reached 200km for the year so far.

USRPT distance this year: 165,800m
Total distance this year: 201,300m

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Building an observatory. Construction #79

I’m pleased to be able to relate that all the mains wiring in the observatory is now complete and it is connected up to the existing supply from the house. I no longer have extension leads and trailing sockets all over the place which is a big improvement, to say the least.

Yesterday I had quite a big tidy up to get rid of most of the stuff that’s been hanging about “in case I need it” which has also improved things by making much more space. I also refitted the desk (previously removed to make it easier for the cabling to be done) and got most of the trunking finished.

Today I made up a shelving unit to go under the desk so I’d have somewhere to put the 12V PSUs in the warm room and then cut up a discarded length of twin core cable with nice fat conductors (it was on a cement mixer until someone managed to break one end) to feed 12V from the PSUs to the cabling running under the floor. Once that was done I made up the connections at the pier ends. All this whilst repeatedly rolling the roof on and off due to random showers. I could have just left the roof closed, but it was unpleasantly humid here today (I think it was about 90% RH at one point) and I wanted all the ventilation I could get. After that I undertook a ridiculously paranoid level of testing as I was very keen not to feed the wrong polarity to a NEQ6, before powering a mount up and using the handset to point it at whatever objects I thought might be in the afternoon sky (all obscured by clouds, sadly). Apparently Mercury, Venus and the Moon were all there somewhere and Jupiter was just creeping above the eastern horizon.

Finally I took down one of the computers that I intend to use on the piers and connected it up inside the box on one of the piers. It’s all a bit scruffy at the moment, but it might allow me to do a bit of testing later in the week.

At this point I think all that remains in terms of cabling is finshing the network cables (putting the RJ45 plugs on, basically) and deciding on the final routing for the cabling for the power supply for the scope room lights. They’re powered from a 24V PSU that I intend plug into a standard 13A socket in the warm room. I just need to come to a decision about routing the cable between the two and get it sorted. There’s probably no major rush for that though, as I can feed them from one of the IP66 sockets on the warm room wall for the time being.

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Swimming, 2nd August 2019

Either the pool was slightly cooler today or I’m getting used to it, though it was clearly still too warm to be comfortable. Hopefully things will start to sort themselves out next week given that the forecast temperatures are only around 20C.

USRPT distance this year: 165,800m
Total distance this year: 199,500m

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Swimming, 1st August 2019

I’m starting to find myself wishing for bad weather, which can’t be a good thing in the best summer we’ve had for a decade, quite possibly. I’d swim elsewhere but the other local pools aren’t very convenient to get to, and the water at the shallow end of the best one doesn’t even come up to my waist 🙁

USRPT distance this year: 165,800m
Total distance this year: 197,700m

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Swimming, 31st July 2019

The pool temperature issue is getting a bit wearing now. It’s not enjoyable trying to swim when it’s over 31C. Apparently the pool heating is turned down as low as it will go. It does make we wonder how much heat is just wasted to the environment in normal use.

USRPT distance this year: 165,800m
Total distance this year: 195,900m

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