Red Hat Enterprise Linux (RHEL) is a commercially supported Linux distribution.
44
votes
7answers
7k views
What is the Linux equivalent to C:\Program Files?
I understand that in Windows as well as Linux and Unix, a program|application|software can be installed in any directory. Also if packages are installed using the distribution's packaging system, ...
16
votes
6answers
17k views
Is CentOS exactly the same as RHEL?
I'm sure this question has been asked again and again elsewhere (I did not find anything specific to CentOS vs RHEL in SE), but I would still like to ask and confirm a few specific points.
I am well ...
14
votes
3answers
865 views
Piping from grep to awk not working
I am trying to grep the ongoing tail of file log and get the nth word from a line. Example file:
$ cat > test.txt <<EOL
Beam goes blah
John goes hey
Beam goes what?
John goes forget it
Beam ...
13
votes
4answers
1k views
What makes CentOS “enterprisey” compared to “generic” distributions like Ubuntu?
What makes CentOS "enterprisey" compared to "generic" distributions like Ubuntu?
When I say "enterprisey" I actually mean "better for server deployments". Just a general question, because I was ...
12
votes
3answers
689 views
how to run new software without updating GLIBC?
I installed Mathematica 9 on an old Red Hat Enterprise Linux AS release 4 system.
After the installation, I tried to start Mathematica, but following message came out:
...
11
votes
6answers
2k views
Is there a difference of stability between Linux distros?
I've using Debian since 2010 for some home purposes and it has been stable. Is Debian still a good option if I need a server for heavy network, cpu, disk and memory usage?
Last month I listened to ...
10
votes
3answers
5k views
Does RHEL execute all cronjob files under /etc/cron.d/*?
This is a RedHat Enterprise Linux 5 system (RHEL). We manage this system using Cfengine.
We have several cronjobs which are running twice as often as usual. I checked the cronjobs under /etc/cron.d/ ...
10
votes
3answers
7k views
Open a RPM on a Mac?
I am on a MacBook Pro running Apple Leopard (Mac OS X 10.5.8).
I would like to unpackage a RPM and view the files contained within the wget-1.11.4-2.el5_4.1.src.rpm . I don't need to install the ...
8
votes
2answers
8k views
How can I increase open files limit for all processes?
I can use ulimit but I think that only affects my shell session. I want the limit increased for all processes. This is on Red Hat.
8
votes
1answer
355 views
Bandwidth control in linux
How do I control both the inbound and outbound bandwidth in a RHEL 5 router?
7
votes
4answers
247 views
What distro is the most similar to RHEL 5?
I'm trying to get used to work with linux for a new job, where I will be using RHEL 5, but right now don't have $179 to buy the workstation version from Red Hat store.
What free distro would be the ...
7
votes
1answer
330 views
Why does Red Hat Linux use such an old kernel?
Why does RHEL (and its derivatives) use such an old kernel? It uses 2.6.32-xxx, which seems old to me. How do they support newer hardware with that kernel? As far as I know these kind of distributions ...
7
votes
1answer
212 views
How to stop users from Switching to Root user
I have disabled the root user login from Sshd.conf file so now no one can login using root user even if they know the password SOMEHOW.
Now I have 3 users in server ROOT,EMERG and ORACLE. I want to ...
7
votes
2answers
979 views
Once sudo su'd to root, is there a command to see my username?
I have sudo rights on a redhat box; once I've "sudo su -" to become root in a shell, are there any commands I can run to see what username I su'd FROM?
7
votes
4answers
1k views
How to install software on Red Hat?
What's the simplest way to download/install software on Red Hat Linux (from bash command line)?
7
votes
2answers
124 views
Are RPMs valid across platforms?
I'm a little confused about RPM's in Red Hat and/or Fedora (and/or other distros?). I can certainly accept that 64-bit RPM's are needed for 64-bit OS'es and 32-bit for 32-bit OS'es but... If I have ...
6
votes
4answers
4k views
can we know the password for the other users if we have root access?
If a person has root access to a particular RHEL machine, will they be able to retrieve the password of the other users?
6
votes
1answer
414 views
What happens when Redhat says: “no more RHEL clones!”
I mean that ex.: CentOS, and Scientific-Linux are the "exact copies" of Redhat Linux. If Redhat would say one day: "I don't allow Redhat clones from now on, I will modify the licence", then what would ...
6
votes
1answer
3k views
Install g++ when having gcc (C only) — RH6
I have a RedHat 6 machine, which came with gcc but without g++.
The gcc version is 4.4.4 20100726 (this is what I got from gcc --version).
How can I get g++ working? Currently, the shell just returns ...
6
votes
4answers
564 views
Is there a pbuilder-like environment for RedHat?
I would like to know if is there any utility like Debian's pbuilder, to build RPM packages on RedHat using a clean environment (chroot).
I've found mach which has support for something like this but ...
6
votes
2answers
86 views
Installing a package locally to a user - best practices?
I want to install Git locally to a user on a RHEL server (I don't have root access)
What would be your cleanest/ most organized way of installing software to a local user account?
Installing ...
6
votes
3answers
4k views
How can I avoid “Run fsck manually” messages while allowing experimenting with system time changes?
I'm working with a system where we want to allow users to play around with the date and time if they want, and where reboots may happen arbitrarily. This is fine, except for one thing: if there's a ...
6
votes
2answers
4k views
Effect of entries in /etc/securetty
By default on RHEL 5.5 I have
[deuberger@saleen trunk]$ sudo cat /etc/securetty
console
vc/1
vc/2
vc/3
vc/4
vc/5
vc/6
vc/7
vc/8
vc/9
vc/10
vc/11
tty1
tty2
tty3
tty4
tty5
tty6
tty7
tty8
tty9
tty10
...
6
votes
2answers
256 views
How to choose LUKS encryption when installing RHEL 6?
With the default RHEL 6 installer, how can I choose the LUKS encryption?
Afaik if I prepare the disk like
cryptsetup luksFormat -c cast5-cbc-plain -s 128 /dev/$DEVICE
could be the "fastest" ...
6
votes
1answer
356 views
Why does `man -k cron` say `vixie-cron (rpm)` for some results, and how do I read those pages?
I'm trying to find out some details regarding cron and /etc/cron.d/ on a RedHat system. Ironically, my answer is viewable within the vixie-cron-*.src.rpm for this package, but the the man pages for ...
5
votes
4answers
437 views
What's the difference between a hard links and copied files?
RHEL 6
My understanding is that hard links include a copy of the original file and that I could delete a hard-linked file in one directory, and it would still exist in the other directory.
If ...
5
votes
1answer
2k views
Unable to delete file, even when running as root
I am in the process of migrating a machine from RHEL 4 to 5. Rather than actually do an upgrade we have created a new VM (both machines are in a cloud) and I am in the process of copying across data ...
5
votes
3answers
107 views
git command not found
I had to install git from source on RHEL. After installation the git command is shown to be in /usr/local/bin/git when trying the whereis command.This path is available in $PATH also.
When I type ...
5
votes
2answers
223 views
Which of these three commands is telling the TRUE Redhat release information
I was checking for the Redhat release so this time I used three different commands. Two commands gave the same result but the third command gave different result. Which one is right.
...
5
votes
3answers
1k views
Getting the password expire time
Let me preface this with: I do NOT have root access available.
I recently got locked out of my account because I did not know the password expiration was getting close, then elapsed. I want to add a ...
5
votes
2answers
1k views
#!/bin/bash - no such file or directory
I've created a bash script but when I try to execute it, I get
#!/bin/bash no such file or directory
I need to run the command: bash script.sh for it to work.
How can I fix this?
5
votes
2answers
18k views
Static IPv4 & IPv6 configuration on CentOS 6.2
I try to configure static IPv4 & IPv6 configuration on CentOS 6.2.
The configuration below works perfectly :
# ifconfig eth0 x.x.x.x/29
# route add defalt gw x.x.x.y
# ip addr add dev eth0 ...
5
votes
2answers
181 views
Can I start my main desktop graphical session remotely?
So my workstation at work got rebooted and I'm currently not logged in physically there with a graphical session. I have ssh access to it, and I can start a new X windows session and use my graphical ...
5
votes
2answers
200 views
Is it possible to create a directory and file inside /proc/sys?
I am running CentOS 6.2 and I need to create a subdirectory named "crypto" inside /proc/sys. Inside /proc/sys/crypto, I need to create a file named test which contains the value "1".
I have tried ...
5
votes
1answer
5k views
How do I install g++ on RHEL6?
This question seems to have been asked here already. My IT department installed the OS so I don't know how to register it properly but I do have root access. Is there a way to get the same packages ...
5
votes
2answers
818 views
How can I serve a Kickstart file over the network without a DHCP server?
I want to install CentOS 5.5 on two systems. I have a kickstart file.
I would like to install CentOS on a system using this kickstart file. I'm reading the instructions provided by fedoraproject.org ...
5
votes
2answers
340 views
How to get started with CentOS?
I've been working with Debian GNU/Linux for a long time and am very proficient with it.
However for a new project I've got to got familiar with CentOS ASAP.
So my Question is: How do I get started ...
5
votes
1answer
2k views
Is there any difference between e2fsck and e4fsck on CentOS / RHEL systems?
ext4.wiki.kernel.org makes it sound like e2fsck was simply renamed to e4fsck so that e4fsprogs and e2fsprogs could coexist without overlapping. However, there is no mention of any difference in the ...
5
votes
2answers
652 views
What roles do DAC (file permissions), ACL and MAC (SELinux) play in Linux file security?
I need some clarification/confirmation/elaboration on the different roles DAC, ACL and MAC play in Linux file security.
After some research from the documentation, this is my understanding of the ...
5
votes
1answer
1k views
Why does redirection (>) not work sometimes but appending (>>) does?
While studying for the RHCE, I came across a situation where stdin redirection does not work in bash:
# file /tmp/users.txt
/tmp/users.txt: cannot open `/tmp/users.txt' (No such file or directory)
...
5
votes
3answers
353 views
Why is the theoretical RAM limit for RHEL 6 128 TB and how is this determined?
I'm studying for RHCSA and am confused by a statement I came across in some training material:
There is no practical maximum RAM, as theoretically, you could run 128 TB of RAM on RHEL 6. But ...
5
votes
2answers
438 views
How to continuously take backup of log files?
I have some applications in Lunux which creates Log files of around 41 MB each. The log files switches from log.1 to log.2 and starts overwriting log.2 once this 41MB is completed in log.1 file.
I ...
5
votes
1answer
249 views
Run script when specific users logout
I need to run my application in screen when specific users are logged out and kill the screen when someone from my user list logged in. So I am thinking about bash script, which will be called ...
5
votes
2answers
141 views
Mailman / Postfix Configuration Assistance
I am writing for some help regarding Postfix configuration.
I cannot seem to get Postfix configured properly to transfer mail to the mailing list installed on the same server. I followed many steps ...
4
votes
5answers
2k views
Does AIX really beat Red Hat Enterprise Linux?
Our company plan to upgrade our servers, and at the same, we would use AIX over Red Hat Enterprise Linux.
I asked my boss the reason of choosing AIX, he said it is because AIX is more powerful. I ...
4
votes
2answers
2k views
.bash_profile not sourced when running su
I have a user, say user1, which has modifications to its .bash_profile, one of them changing the PATH, e.g.: export PATH=/some/place:$PATH. This change works fine if I log on as user1 or do a su - ...
4
votes
3answers
407 views
Linux distribution with 'yum' package manager
I hope that this question is appropriate for this site (if not, please accept my apologies). I am a professional statistician who uses the statistical programming language R. I'm currently building ...
4
votes
2answers
82 views
Why would I want to create more partitions if RHEL will only recognize up to 16?
During some basic RHEL training, I came across this blurb:
Although it's possible to create more, RHEL will recognize only up to 16 partitions on any individual SATA, SCSI, PATA, or virtual hard ...
4
votes
3answers
620 views
Performing accurate snapshot and incremental backups to a remote server
I have a few Ubuntu (and potentially RHEL) servers I'd like to back up to a central backup server (via rsh/SSH). I'd like to do both snapshot and incremental backups. The goal is that if one of the ...
4
votes
2answers
1k views
/dev/tcp listen instead of nc listen
With a netcat listener like:
nc -l <port> < ~/.bashrc
I can grab my .bashrc on a new machine (doesn't have nc or LDAP) with:
cat < /dev/tcp/<ip>/<port> > ~/.bashrc
My ...
