monitoring the integrity of a RAID is critical for fast replacement of failed harddisks (ideally one has at least one spare drive already in the machine) if not – it would be great if hard- and software-raid would send a […]

Mail Server (MTA) Market share: Server Type Number of Servers Percent Exim 507,200 57.13% Postfix 308,036 34.70% Sendmail 34,948 3.94% MailEnable 18,921 2.13% MDaemon 7,464 0.84% Microsoft 4,706 0.53% IMail 1,375 0.15% CommuniGate Pro 1,263 0.14% XMail 783 0.09% Qmail […]

# tested on yum install inxi inxi -b System: Host: hp.centos Kernel: 5.1.15 x86_64 bits: 64 Desktop: MATE 1.16.2 Distro: CentOS Linux release 7.6.1810 (Core) Machine: Type: Server System: HP product: ProLiant DL360 G6 v: N/A serial: XXXXXXXXX Mobo: N/A […]

sometimes one wants to restart a windows vm every x days – to clean up RAM and Co. run task scheduler “Aufgabenplanung” %windir%\system32\taskschd.msc /s File/Datei -> New/Neu -> Basic Task/Einfache Aufgabe select or copy paste: %SystemRoot%\System32\shutdown.exe one has to scroll […]

bc is a nice calculator that one can use under linux terminal. a good exercise: count from 0 to 255 and convert it to binary # install # debian/ubuntu apt install bc # fedora/redhat/centos yum install bc # run bc […]

TLS v1.1 is labeled insecure, TLS v1.2 is current, TLS v1.3 is about to become current. the (e)mail system from 1972 (slightly modified) is still the #1 communication channel, if one believes one’s surveys. The current approved version of TLS […]

update: safety first! when it comes to important files: safety comes first thus recommend to the user that wants to go pro the following backup system: have two complete backups at two different places: backupA: at the company, USB 3.0 […]

this is, because this is, because, when one logs in, and opens another shell as the same user, the last bash process to quit, will save to ~/.bash_history overwrite history. to avoid this add: (TEST IN PROGRESS (UNTESTED)!) # Avoid […]

# tested on Debian 10 su – root; # become root apt update; apt install dnsutils dig -v DiG 9.11.5-P4-5.1+deb10u2-Debian # tested on CentOS Linux 7 (Core) dig -v DiG 9.9.4-RedHat-9.9.4-74.el7_6.1 vim /scripts/what_is_my_public_ip.sh echo “my public (internet facing) ip is:” […]

even the most basic service is valuable, if it can perform reliably

it is actually possible to open a text file in less, then switch over to vim (without exiting less) and when done with editing, switch back to less. less /open/this/file/for/viewing # switch over to vim :v # now one is […]

the syntax -how to output recent date and time to log file of the date command is like this: echo “firewall started on: $(date ‘+%Y-%m-%d_%H-%M-%S’)” >> /var/log/firewall.log other examples: date ‘+%Y-%m-%d-%H:%M:%S’ # or echo $(date ‘+%Y-%m-%d-%H:%M:%S’) # create a file […]

THE ECB BIRD WAS HACKED! “however, the internal system of the Bank has not been compromised” the site http://www.banks-integrated-reporting-dictionary.eu/ was taken offline. It is fascinating. The Europeans probably do not even know about “what is going on” and according to ex […]

got the server cheap from ebay. has unfortunately only 4x 2.5″ SAS (3.5″ would be better = more storage) one SAS drive already faulty. using the native Hardware RAID10 (4x 75GByte Hitachi HGST Ultrastar C10K600 450GB (HUC106045CSS600) 2,5″ SAS2 64MB […]

running esxi inside virtualbox vm is just a test, to play with it, unfortunately one will not be able to start vms on it, because of the lack of nested virtualization. (could/should work nested inside quemu-kvm?) the problem: should have […]

is Rust safer than C/C++? “show me the src” https://github.com/rust-lang https://github.com/rust-lang/rust/tree/master/src DebConf 2019: Why would a python programmer learn rust when there are no jobs in it https://ytpak.net/watch?v=IYLf8lUqR40 “This means no matter what language you use, the only safe way […]

Linux Journal Ceases Publication: An Awkward Goodbye https://www.linuxjournal.com/ IMPORTANT NOTICE FROM LINUX JOURNAL, LLC: On August 7, 2019, Linux Journal shut its doors for good. All staff were laid off and the company is left with no operating funds to […]

update: 2021-03 as the admin-users might have got to know. RedHat canceled long term support for CentOS8, and wants to go with CentOS8stream. so the repo for CentOS8Stream is https://ftp.halifax.rwth-aachen.de/centos/8-stream/BaseOS/x86_64/os/ (https should work, double check for typos) Phase1 setup of […]

Update: kvm is also a good alternative, but only on linux hosts, so if the user plans to move vms between linux and windows hosts, virtualbox is the way to go. Update: 2020-02: VirtualBox 6.1 is available in repository “Debian […]

# how to debug problems # create script vim /scripts/mon_all_logs.sh # fill with this find /var/log/ -type f \( -name “*” \) ! -path ‘*.gz*’ -exec tail -n0 -f “$file” {} + # something is wrong here tail /var/log/Xorg.0.log [ […]

backup/snapshot! first! checkout what releases are available: http://dl-cdn.alpinelinux.org/alpine/ imho one can only upgrade to the next release, not leaving out steps in between. Alpine Linux 3.6.2 # current release running cat /etc/alpine-release 3.6.2 # release one wants to update to […]

Why is quantum computing important: optimization Update: Google claims to have reached quantum supremacy The tech giant unveiled its x-quantum computer chip Bristlecone in March 2018 (src: cnet) original nasa paper: https://drive.google.com/file/d/19lv8p1fB47z1pEZVlfDXhop082Lc-kdD/view book: https://deepai.org/machine-learning/researcher/eleanor-g-rieffel https://www.amazon.com/Quantum-Computing-Introduction-Engineering-Computation/dp/0262015064 Scott’s Supreme Quantum Supremacy FAQ! […]

tar gz (single core) -> tar pigz (multi core) tar might be old, but still a great program for archiving files manpage: tar.man.txt to get multi core usage for compression (faster) the user tells tar to use a different compression […]

screw Qualcomm, what one wants is should work out of the box with recent Linux kernels on Open Source drivers only: https://dwaves.de/2019/07/03/recommended-tested-hardware-superb-wifi-wlan-adapter-chipset-atheros-ar9285-mini-pcie-for-gnu-linux-debian-10-ubuntu-and-trisquel-8-0-test-run-on-lenovo-t440-and-librebooted-lenovo-x60s/ as far as i understand this… if you are concerned about the security of your phone… (banking apps… […]

especially in times of EU-GDPR–DSGVO but also for the user’s privacy effectively shredding data is important. if the admin-user wants to wipe-shred-secure-delete entire harddisks look at this article. GNU Linux Debian 10 can do that 🙂 update: 2024: want to […]

Cinnamon desktop developed by Developer(s) Linux Mint team! – is a beautiful desktop (default on Linux Mint) alternative to Gnome2 MATE. BUT: still prefer Gnome2 MATE (at least on GNU Debian Linux) because it is: minimalistic / very resource efficient […]

per default ls only shows time in hh:mm, if you also need hh:mm:ss you can use: –full-time # show file and folder dates also in milliseconds ls –full-time # the manual says # –full-time is equal to -l –time-style=full-iso # […]

# setup log of VirtualBox Graphical User Interface Version 6.0.10 r132072 (Qt5.7.1) # on Debian 9.8 with Cinnamon Desktop # go into software repo user@debian98:~$ cd /software/ # download latest version of software user@debian98:/software$ wget https://download.virtualbox.org/virtualbox/6.0.10/virtualbox-6.0_6.0.10-132072~Debian~stretch_amd64.deb –2019-08-03 14:36:05– https://download.virtualbox.org/virtualbox/6.0.10/virtualbox-6.0_6.0.10-132072~Debian~stretch_amd64.deb Resolving […]

while not officially supported no drivers here: https://www.wacom.com/en-us/support/bamboo-support works out of the box on CentOS7/Rhel7, Kernel 4.15.9 THIS WORKS ABSOLUTELY INCREDIBLE 🙂 THANKS ALL INVOLVED! # what os do i have? hostnamectl Operating System: CentOS Linux 7 (Core) CPE OS […]

“Linux desktop remains an unpopular choice among mainstream desktop users, making up a little more than 2% of the desktop operating system market share. This is in contrast to the web server market share, which consists of 70% of Linux-based operating systems. […]