Server Fault Stack Exchange
Server Fault Stack Exchange

Most Popular

more tags
1500 questions
156
votes
13 answers

Are networks now faster than disks?

This is a software design question I used to work on the following rule for speed cache memory > memory > disk > network With each step being 5-10 times the previous step (e.g. cache memory is 10 times faster than main memory). Now, it seems that…
pm100
  • 1,655
154
votes
5 answers

How do I make ssh fail rather than prompt for a password if the public-key authentication fails?

I've got a script that SSHes several servers using public key authentication. One of the servers has stopped letting the script log in due to a configuration issue, which means that the script gets stuck with a "Password:" prompt, which it obviously…
rjmunro
  • 2,331
  • 4
  • 18
  • 22
154
votes
3 answers

Delete Amazon EC2 terminated instance

I created an Amazon Free tier Usage Account. I launched two amazon ec2 instances using the online tool. After that one instance was created and running while other was pending which quickly shifted to terminated state. In description it shows State…
Anubhav Agarwal
  • 1,673
154
votes
19 answers

How to add a timestamp to bash script log?

I have a constantly running script that I output to a log file: script.sh >> /var/log/logfile I'd like to add a timestamp before each line that is appended to the log. Like: Sat Sep 10 21:33:06 UTC 2011 The server has booted up. Hmmph. Is there…
Antonius Bloch
  • 4,770
153
votes
9 answers

What version of RHEL am I using?

From the shell and without root privileges, how can I determine what Red Hat Enterprise Linux version I'm running? Ideally, I'd like to get both the major and minor release version, for example RHEL 4.0 or RHEL 5.1, etc.
Arthur Ulfeldt
  • 3,289
152
votes
7 answers

Make nginx to pass hostname of the upstream when reverseproxying

I run several docker containers with hostnames: web1.local web2.local web3.local Routing to these done based on hostname by nginx. I have a proxy in front of this setup (on different machine connected to internet) where I define upstream as: …
pavel_karoukin
  • 1,651
152
votes
13 answers

How do I find the UUID of a file system?

I'm running Ubuntu, and want to find out the UUID of a particular filesystem (not partition). I know I can use e2label /dev/sda1 to find out the file system label, but there doesn't seem to be a similar way to find the UUID.
Brad Gilbert
  • 2,533
152
votes
13 answers

How to set up Nginx as a caching reverse proxy?

I heard recently that Nginx has added caching to its reverse proxy feature. I looked around but couldn't find much info about it. I want to set up Nginx as a caching reverse proxy in front of Apache/Django: to have Nginx proxy requests for some (but…
Continuation
  • 3,130
151
votes
2 answers

Is it possible to make Nginx listen to different ports?

I created one Nginx with one Linux Azure VM, is it possible to make nginx listen to different ports so that when I change the port number, the content would be different. I found there would be a collision if I created two or more ports related to…
billcyz
  • 1,780
151
votes
5 answers

What is the difference between authentication and authorization?

Basic question from a novice: What is the difference between authentication and authorization?
Kyy
151
votes
2 answers

What is Active Directory Domain Services and how does it work?

This is a Canonical Question about Active Directory Domain Services (AD DS). What is Active Directory? What does it do and how does it work? How is Active Directory organized: Forest, Child Domain, Tree, Site, or OU I find myself explaining some…
MDMarra
  • 101,023
151
votes
2 answers

How do VLANs work?

What are VLANs? What problems do they solve? I'm helping a friend learn basic networking, as he's just become the sole sysadmin at a small company. I've been pointing him at various questions/answers on Serverfault relating to various networking…
Murali Suriar
  • 10,326
150
votes
9 answers

Monday morning mistake: sudo rm -rf --no-preserve-root /

Please note: The answers and comments to this question contains content from another, similar question that has received a lot of attention from outside media but turned out to be hoax question in some kind of viral marketing scheme. As we don't…
Jonas Bylov
  • 1,613
150
votes
5 answers

Job scheduling using crontab, what will happen when computer is shutdown during that time?

I schedule some tasks using crontab. What will happen if my computer is shutdown or turned off during the time when cron was scheduled to do something? Does each missed cron job run after computer is turned on, or are missed jobs for that day…
seg.server.fault
  • 1,937
150
votes
8 answers

How do I rename a task in Task Scheduled on Windows Server 2008 R2

I have some tasks in the Task Scheduler on Windows 2008 R2. I created them as the admin and I'm logged in as the admin. I have no easy way to rename the tasks. The only way I can is to export the task config to a XML file and re-import to a new…
Mark
  • 2,111
1 2 3
…
99 100