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1500 questions
74
votes
2 answers

Multiple public keys for one user

This question is similar to SSH public key authentication - can one public key be used for multiple users? but it's the other way around. I'm experimenting on using ssh so any ssh server would work for your answers. Can I have multiple public keys…
Russell
  • 887
74
votes
5 answers

How can I monitor what logrotate is doing?

How can I monitor what logrotate is doing in Ubuntu? Can the activity of logrotate be monitored?
user56548
74
votes
5 answers

Active Directory explained

If you had to explain Active Directory to someone how would you explain it?
user6848
74
votes
6 answers

How do I delete a route from Linux routing table

This turns out to be harder than I thought. The routes I want to delete are the "!" rejected routes, but I can't seem to formulate the right "route del" command to pull it off. Here is the routing table... Destination Gateway Genmask …
user54259
74
votes
12 answers

Do you have any useful awk and grep scripts for parsing apache logs?

I can use log analyzers, but often I need to parse recent web logs to see what's happening at the moment. I sometimes do things like to figure out top 10 ips that request a certain file cat foo.log | grep request_to_file_foo | awk '{print $1}' | …
deadprogrammer
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74
votes
7 answers

iptables equivalent for mac os x

I want to forward requests from 192.168.99.100:80 to 127.0.0.1:8000. This is how I'd do it in linux using iptables: iptables -t nat -A OUTPUT -p tcp --dport 80 -d 192.168.99.100 -j DNAT --to-destination 127.0.0.1:8000 How do I do the same thing in…
nafe
  • 1,281
73
votes
5 answers

The right way to keep docker container started when it used for periodic tasks

I have docker container with installed and configured software. There is no any programm supposed to be started/runned all the time. What I want - its ability to start some command depending on external events. like: docker exec mysupercont…
73
votes
8 answers

Set gitlab external web port number

How do I change gitlab's default port 80 to a custom port number? There are two approaches I've tried: Set the port in /etc/gitlab/gitlab.rb external_port "8888" Then run reconfigure: gitlab-ctl reconfigure Set port in…
73
votes
3 answers

How to test a LDAP connection from a client

How to check the LDAP connection from a client to server. I'm working on the LDAP authentication and this client desktop needs to authenticate via a LDAP server. I can SSH to the LDAP server using LDAP user but When in desktop login prompt, I can't…
FELDAP
  • 979
73
votes
7 answers

How to correct Postfix' 'Relay Access Denied'?

This morning, in order to correct a problem with a name mismatch in the security certificate, I followed the recommended steps from How to fix mail server SSL?, but now, when attempting to send an email from a client (in this case the client is…
Noah Goodrich
  • 19,877
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…
73
votes
6 answers

How to check disk I/O utilization per process?

I'm having a problem with a Linux system and I have found sysstat and sar to report huge peaks of disk I/O, average service time as well as average wait time. How could I determine which process is causing these peaks the next time it happen? Is it…
73
votes
11 answers

How can I choose between using my ISP's DNS, or Google's 8.8.8.8?

It seems like a good idea to use Google's public DNS 8.8.8.8 and 8.8.4.4 because it's really fast -- much faster than my own ISP's DNS! -- and probably more reliable, too. That seems like a ridiculously quick win for me, and much easier to…
73
votes
1 answer

How long does it take for DNS records to propagate?

This is a Canonical Question about DNS Propagation How long does it take for an the various types of records to propagate? Do some propagate faster than others? Why does it take time for DNS records to propagate and how does it work?
user38535
73
votes
6 answers

Sending cron output to a file with a timestamp in its name

I have a crontab like this on a LAMP setup: 0 0 * * * /some/path/to/a/file.php > $HOME/cron.log 2>&1 This writes the output of the file to cron.log. However, when it runs again, it overwrites whatever was previously in the file. How can I get cron…