Linux-Computers

I’m running a TrueNAS Server using the Asus ROG STRIX B550-F GAMING motherboard. Because of all the peripherals like a LSI® SAS 9300-8i PCI Express card for my SAS disks, I didn’t have enough PCI lanes to run a “normal” graphics card. So I got an old Nvidia Quadro NVS 290 NVS290 PCIe x1 card that only uses one PCI lane and fits into a X1 PCI slot. But I would rather run the box without a graphics card and boot headless. But all the information on the internet told me that the Asus ROG STRIX B550-F GAMING Motherboard could not run headless. After several tries, nothing worked. But I finally found a solution ...

I’ve decided to learn how to program FPGA:s. So I got myself two Terasic boards, one Terasic DE10-Nano for testing out the excellent MiSTer FPGA hardware arcade/computer/console emulator and a simpler DE0-Nano for beginning to learn Verilog. But the software used, called Intel Quartus Prime 19.1, is truly horrible. The Windows version doesn’t work with high-resolution screens when using scaling; the text is cut off on the display. So I installed it on my Linux Ubuntu 18.04 machine instead. Now the display works, but there’s a lot of other problems, like getting the dreaded error message: “USB-Blaster unable to scan device chain”. I’ve written them down here for later reference, and maybe you have the same install problems, so this might help. ...

My wild guess is that most people get a small Linux computer, like the Raspberry Pi, BeagleBone, Banana Pi or Orange Pi for a specific task. Unfortunately, most distributions are chock-full of software, with everything installed per default. But if you want to set up a lean single board computer for a specific task, you’re out of luck. Thankfully there is a Linux distribution, DietPi, that aims to fix that problem. ...

Warning: as of yet, there is no official support for overclocking the Raspberry Pi 3, so you could damage your small computer. Just a reminder. Update: I’ve managed to make a DIY heatsink for the Raspberry Pi 3 for $4, and it’s running stable at 1.5GHz. Click here to read. The new version of Raspberry Pi 3 was released yesterday, so I naturally had to get two. I’m using two as Stratum-1 NTP servers, and with the old Raspberry Pi 2, I had hit the roof when it came down to getting better time resolution. So when I read that a new 50% faster version had been released, I raced to the nearest store and got a couple. I have one experimental NTP server that isn’t handing out time on the internet and another one that is the primary server, connected to the NTP Pool Project. I installed the experimental Raspberry Pi 3 first, so I could test performance and try to overclock it. And it went very well. ...

Update: You can download the Eagle PCB files for the PPS Pulse Width Extender here. The PCB is made to fit the Hammond 1455C802BK enclosure. I have two Stratum-1 NTP servers using Raspberry Pi 2’s as servers. But the two setups are entirely different. My primary NTP Stratum-1 server is available at ntp.jacken.se, but it is also in the .se pool of ntp.org. It’s a Raspberry Pi 2 I use a Raspberry Pi 3 that I have connected a U-Blox Neo-7 GPS receiver. But I’m not using the 1 PPS signal coming out of the U-Blox. I have a Trimble GPSDO that I bought from eBay. The unit has two 10 MHz lab reference outputs and one 1 PPS output. But after measuring the signal coming out from the GPSDO, I realized that the timing speed for the seconds “Tick” was only 10 µsec which is way to fast for the Raspberry Pi to pick up as an interrupt on one of the GPIO pins. So I built a pulse extender, making the pulse around 250 milliseconds instead. And now the Raspberry Pi picks up the pulse without problems. Some GPSDO units can set the pulse width by programming the unit via a serial port, but I can’t find that feature on this unit (which is poorly documented and was OEM made for some other manufacturer), so I had to do it with hardware. So how does it look when crunching the numbers on it? ...

Nagios Directory Index Forbidden by Options Directive After installing Nagios on a Raspberry Pi 2 Model B by following these installation instructions, I ran into an irritating problem. When trying to connect, I got the authentication dialog, but after that, I got an access error in my browser. Directory index forbidden by Options directive: /usr/local/nagios/share I searched around on Google but couldn’t find a solution. But after a lot of fiddling with Apache2, I found a solution. There’s a problem with the standard installation of the file in /etc/apache2/conf.d/nagios.conf created by make install-webconf ...

SqueezePlug problem where Squeezelite refuse to start I installed a Raspberry Pi in my livingroom as a Squeezebox music Server/Player, using a SqueezePlug[1] image. But when I tried to install the Squeezelite player, it refused to start. I tried to uninstall and reinstall, selecting another USB Audio Interface, but the problem persisted. After checking around and doing a some experimenting, I found that I could start Squeezelite manually from the terminal prompt, but if I tried to start it with the init.d or service script, it refused to start. So I started to dig around and experimented with changing the settings for Squeezelite and I found the problem… ...

When setting up my new web server I had a problem when installing vsftpd on Ubuntu Server 12.04 LTS. After doing the sudo apt-get install vsftpd and enabling login for local users, I got a “Server 530 login incorrect error” when trying to connect with a local user. The settings for disabling anonymous login and allowing local users where set in /etc/vsftpd.conf. [cc lang=“bash”]anonymous_enable=NO local_enable=YES write_enable=YES[/cc] But the ftp server still refused to let me login with any of the users on the system. I tried remove and reinstall, but the problem persisted. Finally I found a thread where others had the same problem. And here’s how to fix the problem. [cc lang=“bash”] sudo apt-get remove vsftpd sudo rm /etc/pam.d/vsftpd sudo apt-get install vsftpd [/cc] ...

So I finally got my 100 mbit internet connection. Yay! But after testing the speed through my WRT54G router/firewall, I could not get higher speeds than around 20 mbit/sec. After assembling an old 300 mhz pc with three Ethernet cards and the SmoothWall linux firewall I get around 70 mbits/sec. I will probably try to overclock the poor old pc to 400 mhz tomorrow. To try everything out, I downloaded the XCode 2.2.1 development image from Apple. It’s around 800 mb and it took just a couple of minutes. I could get used to this.

So I’ve been busy for the last five days setting up my Asterisk PBX. I’ve connected two different VoIP lines to it. I have the X-Lite VoIP softphones installed on all the computers and an FSX device so I can use my regular wireless phone. And it’s enjoyable learning something new. First, my wife thought that I was crazy, “Who needs a telephone switchboard at home!?” But I think she’s coming around. Now she can sit at her computer using a headset and talk to her friends without holding the line. And it’s easy to transfer calls between all the phones in the apartment. It’s also nice to have a digital answering machine and get the messages mailed to you. The added benefit of multiple lines on the same phone number and that it doesn’t cost anything to dial a phone in Sweden is a bonus. ...