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1500 questions
199
votes
15 answers
How to know from which yum repository a package has been installed?
After I have installed a package by yum (with multiple repositories configured), how can I find from which repository it has been installed?
If I run yum info package-name (or yum list package-name), I can only see that the package is "installed".
lg.
- 4,759
198
votes
9 answers
Resolve host name from IP address
I'm looking for a command line tool which gets an IP address and returns the host name, for Windows.
DouglasJose
- 2,103
198
votes
6 answers
how to disable SSH login with password for some users?
On Linux (Debian Squeeze) I would like to disable SSH login using password to some users (selected group or all users except root). But I do not want to disable login using certificate for them.
edit: thanks a lot for detailed answer! For some…
Stepan
- 2,199
197
votes
8 answers
Filename length limits on linux?
Are there any filename or path length limits on Linux?
readonly
- 3,579
197
votes
6 answers
LVM dangers and caveats
I have recently started using LVM on some servers for hard drives larger than 1 TB. They're useful, expandable and quite easy to install. However, I could not find any data about the dangers and caveats of LVM.
What are the downsides of using LVM?
Adam Matan
- 14,084
197
votes
10 answers
What is "-bash: !": event not found"
Try executing the following under a bash shell echo "Reboot your instance!"
On my installation:
root@domU-12-31-39-04-11-83:/usr/local/bin# bash --version
GNU bash, version 4.1.5(1)-release (i686-pc-linux-gnu)
Copyright (C) 2009 Free Software…
Maxim Veksler
- 2,875
196
votes
6 answers
How to cd into a directory with this name "-2" (starting with the hyphen)?
I have a directory named:
-2
I want to cd into it but the cd complains:
bash: cd: -2: invalid option
With no success, I've tried:
cd "-2"
cd '-2'
cd \-2
Any solution?
Edit: no file browsers like mc, etc. available on the server.
user151851
- 1,863
196
votes
22 answers
Is it normal to get hundreds of break-in attempts per day?
I just checked my server's /var/log/auth.log and found that I'm getting over 500 failed password/break-in attempt notifications per day! My site is small, and its URL is obscure. Is this normal? Should I be taking any measures?
Kyle Cureau
- 1,547
193
votes
2 answers
What are the different widely used RAID levels and when should I consider them?
This is a Canonical Question about RAID levels.
What are:
the RAID levels typically used (including the RAID-Z family)?
deployments are they commonly found in?
benefits and pitfalls of each?
MDMarra
- 101,323
192
votes
6 answers
List of files installed from apt package
How do I get a list of files that were or will-be installed when I apt-get a package? Conversely, can I find what package(s) caused a particular file to be installed?
David Nehme
- 2,436
192
votes
5 answers
I am under DDoS. What can I do?
This is a Canonical Question about DoS and DDoS mitigation.
I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth. Nobody can…
Falcon Momot
- 25,584
192
votes
4 answers
Should I quit using Ifconfig?
With the servers that mount Infiniband cards, when I use the ifconfig command, I get this warning:
Ifconfig uses the ioctl access method to get the full address
information, which limits hardware addresses to 8 bytes.
Because Infiniband address has…
Zhen
- 2,179
191
votes
11 answers
Run an interactive bash subshell with initial commands without returning to the ("super") shell immediately
I want to run a bash subshell, (1) run a few commands, (2) and then remain in that subshell to do as I please. I can do each of these individually:
Run command using -c flag:
$> bash -c "ls; pwd; "
however, it immediately…
SABBATINI Luca
- 1,911
190
votes
8 answers
How do I sleep for a millisecond in bash or ksh
sleep is a very popular command and we can start sleep from 1 second:
# wait one second please
sleep 1
but what the alternative if I need to wait only 0.1 second or between 0.1 to 1 second ?
remark: on linux or OS X sleep 0.XXX works fine , but…
yael
- 2,563
190
votes
5 answers
What is the difference between Load Balancer and Reverse Proxy?
I'm not clear about the difference between Load Balancer and Reverse Proxy. They both seems having same behavior: distributing incoming requests to backend servers.
Morgan Cheng
- 2,244
- 3
- 17
- 13