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<a href=/index.xml target=_blank class=hob>RSS</a></nav></header><main role=main><article itemtype=http://schema.org/Article><h1 itemtype=headline>List of essential Linux commands for server management</h1><p><cap>post</cap>, Aug 1, 2021 on <a href=https://mitjafelicijan.com>Mitja Felicijan's blog</a><div><p><strong>Generate SSH key</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>ssh-keygen -t ed25519 -C <span style=color:#a31515>&#34;your_email@example.com&#34;</span>
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># when no support for Ed25519 present</span>
</span></span><span style=display:flex><span>ssh-keygen -t rsa -b 4096 -C <span style=color:#a31515>&#34;your_email@example.com&#34;</span>
</span></span></code></pre><p>Note: By default SSH keys get stored to <code>/home/&lt;username>/.ssh/</code> folder.<p><strong>Login to host via SSH</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:green># connect to host as your local username</span>
</span></span><span style=display:flex><span>ssh host
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># connect to host as user</span>
</span></span><span style=display:flex><span>ssh &lt;user&gt;@&lt;host&gt;
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># connect to host using port</span>
</span></span><span style=display:flex><span>ssh -p &lt;port&gt; &lt;user&gt;@&lt;host&gt;
</span></span></code></pre><p><strong>Execute command on a server through SSH</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:green># execute one command</span>
</span></span><span style=display:flex><span>ssh root@100.100.100.100 <span style=color:#a31515>&#34;ls /root&#34;</span>
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># execute many commands</span>
</span></span><span style=display:flex><span>ssh root@100.100.100.100 <span style=color:#a31515>&#34;cd /root;touch file.txt&#34;</span>
</span></span></code></pre><p><strong>Displays currently logged in users in the system</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>w
</span></span></code></pre><p><strong>Displays Linux system information</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>uname
</span></span></code></pre><p><strong>Displays kernel release information</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>uname -r
</span></span></code></pre><p><strong>Shows the system hostname</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>hostname
</span></span></code></pre><p><strong>Shows system reboot history</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>last reboot
</span></span></code></pre><p><strong>Displays information about the user</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>sudo apt install finger
</span></span><span style=display:flex><span>finger &lt;username&gt;
</span></span></code></pre><p><strong>Displays IP addresses and all the network interfaces</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>ip addr show
</span></span></code></pre><p><strong>Downloads a file from an online source</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>wget https://example.com/example.tgz
</span></span></code></pre><p>Note: If URL contains ?, & enclose the URL in double quotes.<p><strong>Compress a file with gzip</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:green># will not keep the original file</span>
</span></span><span style=display:flex><span>gzip file.txt
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># will keep the original file</span>
</span></span><span style=display:flex><span>gzip --keep file.txt
</span></span></code></pre><p><strong>Interactive disk usage analyzer</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>sudo apt install ncdu
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>ncdu
</span></span><span style=display:flex><span>ncdu &lt;path/to/directory&gt;
</span></span></code></pre><p><strong>Install Node.js using the Node Version Manager</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash
</span></span><span style=display:flex><span>source ~/.bashrc
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>nvm install v13
</span></span></code></pre><p><strong>Too long; didn't read</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>npm install -g tldr
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>tldr tar
</span></span></code></pre><p><strong>Combine all Nginx access logs to one big log file</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>zcat -f /var/log/nginx/access.log* &gt; /var/log/nginx/access-all.log
</span></span></code></pre><p><strong>Set up Redis server</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>sudo apt install redis-server redis-tools
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># check if server is running</span>
</span></span><span style=display:flex><span>sudo service redis status
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># set and get a key value</span>
</span></span><span style=display:flex><span>redis-cli set mykey myvalue
</span></span><span style=display:flex><span>redis-cli get mykey
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># interactive shell</span>
</span></span><span style=display:flex><span>redis-cli
</span></span></code></pre><p><strong>Generate statistics of your webserver</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>sudo apt install goaccess
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># check if installed</span>
</span></span><span style=display:flex><span>goaccess -v
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># combine logs</span>
</span></span><span style=display:flex><span>zcat -f /var/log/nginx/access.log* &gt; /var/log/nginx/access-all.log
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># export to single html</span>
</span></span><span style=display:flex><span>goaccess <span style=color:#a31515>\
</span></span></span><span style=display:flex><span><span style=color:#a31515></span>  --log-file=/var/log/nginx/access-all.log <span style=color:#a31515>\
</span></span></span><span style=display:flex><span><span style=color:#a31515></span>  --log-format=COMBINED <span style=color:#a31515>\
</span></span></span><span style=display:flex><span><span style=color:#a31515></span>  --exclude-ip=0.0.0.0 <span style=color:#a31515>\
</span></span></span><span style=display:flex><span><span style=color:#a31515></span>  --ignore-crawlers <span style=color:#a31515>\
</span></span></span><span style=display:flex><span><span style=color:#a31515></span>  --real-os <span style=color:#a31515>\
</span></span></span><span style=display:flex><span><span style=color:#a31515></span>  --output=/var/www/html/stats.html
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># cleanup afterwards</span>
</span></span><span style=display:flex><span>rm /var/log/nginx/access-all.log
</span></span></code></pre><p><strong>Search for a given pattern in files</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>grep -r ‘pattern’ files
</span></span></code></pre><p><strong>Find proccess ID for a specific program</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>pgrep nginx
</span></span></code></pre><p><strong>Print name of current/working directory</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>pwd
</span></span></code></pre><p><strong>Creates a blank new file</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>touch newfile.txt
</span></span></code></pre><p><strong>Displays first lines in a file</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:green># -n &lt;x&gt; presents the number of lines (10 by default)</span>
</span></span><span style=display:flex><span>head -n 20 somefile.txt
</span></span></code></pre><p><strong>Displays last lines in a file</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:green># -n &lt;x&gt; presents the number of lines (10 by default)</span>
</span></span><span style=display:flex><span>tail -n 20 somefile.txt
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># -f follows the changes in file (doesn&#39;t closes)</span>
</span></span><span style=display:flex><span>tail -f somefile.txt
</span></span></code></pre><p><strong>Count lines in a file</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>wc -l somefile.txt
</span></span></code></pre><p><strong>Find all instances of the file</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>sudo apt install mlocate
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>locate somefile.txt
</span></span></code></pre><p><strong>Find file names that begin with ‘index’ in /home folder</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>find /home/ -name <span style=color:#a31515>&#34;index&#34;</span>
</span></span></code></pre><p><strong>Find files larger than 100MB in the home folder</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>find /home -size +100M
</span></span></code></pre><p><strong>Displays block devices related information</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>lsblk
</span></span></code></pre><p><strong>Displays free space on mounted systems</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>df -h
</span></span></code></pre><p><strong>Displays free and used memory in the system</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>free -h
</span></span></code></pre><p><strong>Displays all active listening ports</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>sudo apt install net-tools
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>netstat -pnltu
</span></span></code></pre><p><strong>Kill a process violently</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>kill -9 &lt;pid&gt;
</span></span></code></pre><p><strong>List files opened by user</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>lsof -u &lt;user&gt;
</span></span></code></pre><p><strong>Execute "df -h", showing periodic updates</strong><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:green># -n 1 means every second</span>
</span></span><span style=display:flex><span>watch -n 1 df -h
</span></span></code></pre></div></article></main><section><hr><h2>Posts from blogs I follow around the net</h2><ul><li><a href=https://utcc.utoronto.ca/~cks/space/blog/solaris/ZFSWhyNotDirectoryToFilesystem target=_blank rel=noopener>One reason that ZFS can't turn a directory into a filesystem</a> — <a href=https://utcc.utoronto.ca/~cks/space/blog/>Chris's Wiki :: blog</a><div>One of the wishes that I and other people frequently have for ZFS
is the ability to take an existing directory (and everything
underneath it) in a ZFS filesystem and turn it into a sub-filesystem
of its own. One reason for wanting this is that a number of things
are set and controlled on a per-filesyst…<li><a href=http://www.landley.net/notes-2023.html#28-10-2023 target=_blank rel=noopener>October 28, 2023</a> — <a href=http://www.landley.net/notes-2023.html>Rob Landley's Blog Thing for 2023</a><div>Oh good grief, two of my least favorite licensing people, Larry Rosen
and Bradley Kuhn, are interacting on the OSI's license-discuss
list where the're doing
bad computer history and insisting that a guy Larry Rosen
coincidentally interviewed for a book years ago is clearly the origin of
somethin…<li><a href="http://offbeatpursuit.com:80/blog/?id=25" target=_blank rel=noopener>A fix by any other name</a> — <a href=http://offbeatpursuit.com:80/blog/>WLOG - blog</a><div>tags:
i2c, plan9
Another month, another file system.
Well, if you can’t fix it in software, fix it in hardware (looking at
you, bme680, we’re not
done yet). The show must go on, as they say, and I would like my
experiments to go on.
So a “new” addition to the environmental sensor family connected to
the h…<li><a href=https://mirzapandzo.com/next-image-url-parameter-is-valid-but-upstream-response-is-invalid target=_blank rel=noopener>Next/Image "url" parameter is valid but upstream response is invalid</a> — <a href=https://mirzapandzo.com/>Mirza Pandzo's Blog</a><div>Getting "url" parameter is valid but upstream response is invalid error with Next/Image on WSL2<li><a href=https://drewdevault.com/2023/10/13/Going-off-script.html target=_blank rel=noopener>Going off-script</a> — <a href=https://drewdevault.com>Drew DeVault's blog</a><div>There is a phenomenon in society which I find quite bizarre. Upon our entry to
this mortal coil, we are endowed with self-awareness, agency, and free will.
Each of the 8 billion members of this human race represents a unique person, a
unique worldview, and a unique agency. Yet, many of us have the sam…<li><a href=https://szymonkaliski.com/writing/2023-10-02-building-a-diy-pen-plotter/ target=_blank rel=noopener>Building a DIY Pen Plotter</a> — <a href=http://github.com/dylang/node-rss>Szymon Kaliski</a><div>This article documents my learnings from designing and building a DIY Pen Plotter during the summer of 2023.
My ultimate goal is to build my…<li><a href=https://neil.computer/notes/chart-of-accounts-for-startups-and-saas-companies/ target=_blank rel=noopener>Chart of Accounts for Startups and SaaS Companies</a> — <a href=https://neil.computer/>Neil Panchal</a><div>Accounting is fundamental to starting a business. You need to have a basic understanding of accounting principles and essential bookkeeping. I had to learn it. There was no choice. For filing taxes, your CPA is going to ask you for an Income Statement (also known as P/L statement). If<li><a href=https://journal.valeriansaliou.name/deploy-a-nomad-cluster-on-alpine-linux-with-vultr/ target=_blank rel=noopener>Deploy a Nomad Cluster on Alpine Linux with Vultr</a> — <a href=https://journal.valeriansaliou.name/>Valerian Saliou</a><div>After spending countless hours trying to understand how to deploy my apps on Kubernetes for the first time to host Mirage, an AI API service that I run, I ended up making myself a promise that the next app I work on would be using a more productive & simpler<li><a href=https://jcs.org/2023/10/25/wifi_da target=_blank rel=noopener>BlueSCSI Wi-Fi Desk Accessory 1.0 Released</a> — <a href=https://jcs.org/>joshua stein</a><div>BlueSCSI Wi-Fi Desk Accessory
1.0 has been released:
wifi_da-1.0.sit
(StuffIt 3 archive)
SHA256: ccfc9d27dd5da7412d10cef73b81119a1fec3848e4d1d88ff652a07ffdc6a69aSHA1: ff124972f202ceda6d7fa4788110a67ccda6a13a
This is the initial public release of my BlueSCSI Wi-Fi Desk Accessory for
classic MacOS.<li><a href=https://michael.stapelberg.ch/posts/2023-10-25-my-all-flash-zfs-network-storage-build/ target=_blank rel=noopener>My 2023 all-flash ZFS NAS (Network Storage) build</a> — <a href=https://michael.stapelberg.ch/>Michael Stapelbergs Website</a><div>For over 10 years now, I run two self-built NAS (Network Storage) devices which serve media (currently via Jellyfin) and run daily backups of all my PCs and servers.
In this article, I describe my goals, which hardware I picked for my new build (and why) and how I set it up.
Design Goals
I use my netw…</ul><p>Generated with <a href=https://git.sr.ht/~sircmpwn/openring target=_blank rel=noopener>openring</a>.</section><footer><hr><p><big><strong>Want to comment or have something to add?</strong></big><p>You can write me an email
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