Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [linux]

Linux is the generic term for a UNIX-like open source operating system based on the Linux kernel.

GNU/Linux is a UNIX-like Open Source operating system. Linus Torvalds originally wrote the Linux kernel with contributions from others on the MINIX usenet board. Since then, Linux had thousands of developers, both paid by companies and volunteers. The main system tools and libraries for GNU/Linux are sourced from the GNU Project, hence the nomenclature GNU/Linux (GNU Toolchain over Linux Kernel). The Linux kernel is licensed under the GPL v2 license.

There are many different Linux Distributions (sometimes shortened to distro), which consist of software applications packaged and provided with the Linux kernel, being Slackware the oldest active distro and Debian, Red Hat and CentOS among the most used on Internet servers¹.

The Linux kernel is commonly run on servers but is highly portable and is used in a variety of applications, from wireless routers and cell phones to clusters and super computers with thousands of nodes and processors.

External Resources:

38271 questions
74
votes
7 answers

How to specify hostname for the running container?

I'm having trouble setting the hostname on a running docker container. I'm also having trouble understanding how to specify hostname after the image is started. I started a container from an image I downloaded: sudo docker run -p 8080:80 -p 2222:22…
Miguel Ping
  • 865
  • 1
  • 6
  • 9
74
votes
3 answers

What is the difference between /sbin/nologin and /bin/false?

I have often heard it recommended that a user account should be disabled by setting its shell to /bin/false. But, on my existing Linux systems, I see that a great number of existing accounts (all of them service accounts) have a shell of…
Michael Hampton
  • 244,070
  • 43
  • 506
  • 972
74
votes
2 answers

How should an IT department choose a standard Linux distribution?

There is a lot of community feeling about what Linux distributions are appropriate for production server environments and which aren't, however, a lot of this feeling seems religiously based, and seldom presented with supporting evidence. Assuming…
wfaulk
  • 6,878
  • 7
  • 46
  • 75
74
votes
9 answers

How passively monitor for tcp packet loss? (Linux)

How can I passively monitor the packet loss on TCP connections to/from my machine? Basically, I'd like a tool that sits in the background and watches TCP ack/nak/re-transmits to generate a report on which peer IP addresses "seem" to be experiencing…
nonot1
  • 1,099
  • 1
  • 12
  • 16
73
votes
5 answers

Which OS is running in my Docker container?

Most of the time, using one of these two, I can tell which OS is running in my Docker container (alpine, centOS, etc) But this time, I can't tell: bash-4.2$ uname -a Linux 6fe5c6d1451c 2.6.32-504.23.4.el6.x86_64 #1 SMP Tue Jun 9 20:57:37 UTC…
Bob Yoplait
  • 841
  • 1
  • 6
  • 6
73
votes
2 answers

Create a directory under /var/run at boot

I had a daemon that needed its own dir in /var/run for its PID file with write permission granted to the daemon's user. I found I could create this dir with these commands: # mkdir /var/run/mydaemon Then I could change its ownership to the…
user24601
  • 973
  • 1
  • 6
  • 8
73
votes
3 answers

What is the difference between unlink and rm?

Is unlink any faster than rm?
Marcin
  • 833
  • 1
  • 6
  • 4
73
votes
10 answers

xvda1 is 100% full, What is it? how to fix?

I'm running a Linux instance on EC2 (I have MongoDB and node.js installed) and I'm getting this error: Cannot write: No space left on device I think I've tracked it down to this file, here is the df output Filesystem 1K-blocks Used…
Chris Biscardi
  • 831
  • 1
  • 7
  • 5
73
votes
9 answers

Can't find .so in the same directory as the executable?

I have an executable which needs to link with libtest.so dynamically,so I put them in the same directory,then : cd path_to_dir ./binary But got this: error while loading shared libraries: libtest.so: cannot open shared object file: No such file or…
linuxer
  • 733
  • 1
  • 6
  • 4
73
votes
1 answer

Why does htop have three load averages?

On htop, it shows three load averages, one bold, one normal, one red. What do they signify?
chrism2671
  • 2,579
  • 9
  • 34
  • 45
73
votes
7 answers

How to setup linux permissions for the WWW folder?

Updated Summary The /var/www directory is owned by root:root which means that no one can use it and it's entirely useless. Since we all want a web server that actually works (and no-one should be logging in as "root"), then we need to fix this.…
Xeoncross
  • 4,449
  • 12
  • 43
  • 56
72
votes
2 answers

Why is it so difficult to upgrade between major versions of Red Hat and CentOS?

"Can we upgrade our existing production EL5 servers to EL6?" A simple-sounding request from two customers with completely different environments prompted my usual best-practices answer of "yes, but it will require a coordinated rebuild of all of…
ewwhite
  • 197,159
  • 92
  • 443
  • 809
71
votes
6 answers

What should NOT be managed by puppet?

I'm learning my way through configuration management in general and using puppet to implement it in particular, and I'm wondering what aspects of a system, if any, should not be managed with puppet? As an example we usually take for granted that…
Luke404
  • 5,826
  • 4
  • 47
  • 58
71
votes
20 answers

How to create an SHA-512 hashed password for shadow?

The previous SF questions I've seen have lead to answers that produce MD5 hashed password. Does anyone have a suggestion on to produce an SHA-512 hashed password? I'd prefer a one liner instead of a script but, if a script is the only solution,…
Belmin Fernandez
  • 10,799
  • 27
  • 84
  • 148
71
votes
2 answers

How do I edit the crontab of another user on my linux server?

I have a user on my linux server who has sudo. I want to edit the crontab of another user. I'm new to this though and don't understand what the man pages are telling me yet. Man crontab tells me I can use this format for the crontab…
bflora
  • 849
  • 1
  • 6
  • 3
1 2 3
…
99 100