My preferred editor in unix-like systems is vi or vim. VI is everywhere and VIM is improved for scripting and coding.
Sunday, June 1, 2025
Sunday, May 18, 2025
VMware VCF's SDDC Backup over sftp
You can do a native VCF SDDC Manager backup via SFTP protocol. SFTP is a file transfer protocol that operates over the SSH protocol. When using SFTP for VMware VCF's backup, you're effectively using the SSH protocol for transport.
For VCF older than 5.1, you have to allow ssh-rsa algorithm for host key and user authentication on your SSH Server.
It is configurable in SSH Daemon Configuration (/etc/ssh/sshd_config) on your backup server should have following lines to allow ssh-rsa algorithm for host key and user authentication.
Friday, May 9, 2025
RaspberryPi - GPIO control over Web Interface
How to use RaspberryPi inputs and outputs? The easiest way is to use the GPIO pins directly on the RaspberryPi board.
Hardware
Raspberry Pi has 8 freely accessible GPIO ports. which can be controlled. In the following picture they are colored green.
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| GPIO ports |
Attention!!! GPIO are 3.3V and do not tolerate 5V !! Maximum current is 16mA !! It would be possible to use more of them by changing the configuration.
Software
First you need to install the ligthhttpd (or apache ) server and PHP5:
sudo groupadd www-data
sudo apt-get install lighttpd
sudo apt-get install php5-cgi
sudo lighty-enable-mod fastcgi
sudo adduser pi www-data
sudo chown -R www-data:www-data /var/www
In the lighthttpd configuration
you need to add:
bin-path" => "/usr/bin/php5-cgi
socket" => "/tmp/php.socket"
Now you need to restart lighthttpd:
sudo /etc/init.d/lighttpd force-reload
This will run our webserver with PHP.
Now we get to the actual GPIO control. The ports can be used as input and output. Everything needs to be done as root.
First you need to make the port accessible:
echo "17" > /sys/class/gpio/export
Then we set whether it is an input (in) or output (out):
echo "out" > /sys/class/gpio/gpio17/direction
Set the value like this:
echo 1 > /sys/class/gpio/gpio17/valu
Read the status:
cat /sys/class/gpio/gpio17/value
This way we can control GPIO directly from the command line. If we use the www interface for control, we need to set the rights for all ports so that they can be controlled by a user other than root.
chmod 666 /sys/class/gpio/gpio17/value
chmod 666 /sys/class/gpio/gpio17/direction
Saturday, May 3, 2025
How to create a template on XCP-ng with XenOrchestra
"In this post I will show you how to create a template in XenOrchestra and using an image we created and customized ourself. " ... full blog post is available at https://blog.bufanda.de/how-to-create-a-template-on-xcp-ng-with-xenorchestra/
Thursday, February 13, 2025
VMware vSAN ESA on Cisco UCS - TCP Connection Half Open Drop Rate
During the investigation of high disk response times in one VM using vSAN storage, I saw a strange vSAN metric (TCP Connection Half Open Drop Rate).
What is it?
I have opened support ticket with VMware Support (2025-02-13) and started my own troubleshooting in paralel.
Wednesday, February 12, 2025
VMware vs OpenStack
Here are scrrenshot from Canonical webcast
Feature comparison
OpenStack technological stack
System containers (LXD) vs Application Containers (Docker)



