Red Hat Enterprise Linux (RHEL) is a commercially supported Linux distribution.

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27
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3answers
5k views

What is the difference between these commands for bringing down a Linux server?

Reading "What is the difference between Halt and Shutdown commands?" , I generally have an idea what does the command shutdown does, with or without -h/-r options. The "halt" command performs ...
17
votes
4answers
101k views

How can we change root password?

If we don't know the root password and don't have root access to the machine, how can we change the root password?
3
votes
2answers
935 views

Commands for determining level of usage of server

I am scripting a new program that will connect to a cluster of machines in a VM park, and hopefully check their level of usage. The VM clients are a combination of RHEL and CentOS, and runs on ...
22
votes
3answers
17k 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 - ...
69
votes
11answers
112k 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 ...
22
votes
2answers
18k 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 ...
21
votes
3answers
22k 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 ...
7
votes
2answers
48k views

Setup static IP in redhat 6

I installed Redhat 6 x86_64. I am using the Network connection screen to set a static IP address like below (I want two PC's in my house to see each other: one Redhat PC and one Mac) 192.168.0.5 ...
8
votes
2answers
57k views

How to clear memory cache in Linux

Is there any command that by using I can clean the cache in RHEL? I used this command: sync; echo 3 > /proc/sys/vm/drop_caches but it didn't work.
2
votes
1answer
4k views

.bashrc doesn't get executed

I have a user (non-root) which has a ~/.bashrc file with some aliases in it. But it doesn't look like the file is executed at log in time. If I do source ~/.bashrc then it does what it's supposed to. ...
5
votes
3answers
12k views

RHEL: Creating stable names for network interfaces

We have a RHEL 5.5 box with 8 interfaces. And the eth interface naming is flip flopping. Sometimes eth0 comes up on physical port 7th, and sometimes on another physical port. We want the naming to ...
6
votes
4answers
31k views

Pseudo-terminal will not be allocated because stdin is not a terminal

I'm trying to set up automatic SSH hopping through a server which doesn't have nc. This works from the command line: ssh -A gateway ssh steve@target (I have added my public key to the SSH agent). ...
21
votes
1answer
31k 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 ...
17
votes
3answers
18k views

Does RHEL/CentOS execute all cronjob files under /etc/cron.d/*, or just some of them?

This is a Red Hat 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
2answers
11k 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 ...
8
votes
3answers
3k views

Is there a way to install and remove packages in a single yum command?

Is there a way to add and remove packages at the same time with a single yum command? For example, installing postfix and removing sendmail without running two separate commands/transactions.
15
votes
3answers
16k 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
2answers
25k views

Equivalent of update-grub for RHEL/Fedora/CentOS systems?

In Ubuntu (and I guess in Debian too) there is a system script named update-grub which automatically executes grub-mkconfig -o with the correct path for the grub configuration file. Is there any ...
3
votes
1answer
2k views

Systemd kills service immediately after start

I'm writing systemd unit file for OSSEC HIDS. Problem is that when systemd starts service it immediately stops them. When I use that ExecStart directive all working fine. ...
3
votes
1answer
942 views

Writing triggers for mcelog

Just starting to look into mcelog for the first time (I've enabled it and seen syslog output before, but this is the first time I'm trying to do something non-default). I'm looking for information on ...
1
vote
1answer
32k views

Uninstall JDK rpm to reinstall

Where do I find the JDK install to uninstall? @terdon had explained using an rpm type download so it would be easier to uninstall, but I cannot find it.
17
votes
7answers
6k 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
1answer
8k views

How do I reduce the size of locale-archive?

I have a need to reduce the size of the locale-archive file on some of my RHEL6 systems. Here is that file on my system: [root@-dev-007 locale]# ls -l total 96800 -rw-r--r--. 1 root root 99158704 ...
10
votes
1answer
29k 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 ...
9
votes
2answers
8k views

How can I install ncdu on Red Hat?

The answers provided to this question doesn't help. I'ved tried yum install ncdu But I'm getting No package ncdu available
5
votes
1answer
20k views

BOOTPROTO=none | static | dhcp and /etc/resolv.conf

What does it mean when it says BOOTPROTO=none in the /etc/sysconfig/network-scripts/ifcfg-eth0 file. I remember there used to be BOOTPROTO=static and it was very clear and straight-forward in telling ...
3
votes
1answer
2k views

Can I automate mounting a cifs share without storing my password in plaintext?

I currently use a script which contains commands along the lines of sudo /sbin/mount.cifs $SERVER_SHARE $MOUNT -o username=$DOMAIN_$USER,uid=$USER,gid=$USER,file_mode=0664,dir_mode=0775 to mount my ...
1
vote
4answers
19k views

Why VNC not showing actual Remote Desktop

Ok i installed vnc server on RHEL 5.9 and also installed Tightvnc viewer on windows 7 and from RHEL i started vncserver and assigned the password using vncpasswd. Then from tightvnc viewer i gave the ...
1
vote
1answer
8k views

doing OpenLDAP config changes in RHEL 6

I've been configuring OpenLDAP on RHEL 6 and its seems you have run the following to rebuild the config dirs. I'm ok with that, but my issues is, say I want to change the server passwd, do I have to ...
12
votes
4answers
8k views

What are the dangers of creating a normal user with UID < 500?

What are the dangers of creating a normal user with UID < 500? Assuming the UID's are not duplicates of existing UID's, what could go wrong? This is not something that I want to do, but something ...
8
votes
4answers
16k 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)?
4
votes
2answers
1k views

Separate Network Traffic on Two Network Interfaces

I am not an R&S professional, so much of that realm of computing escapes me. Could you lend your expertise in helping understand how to go about configuring the separation of network traffic on ...
4
votes
3answers
23k views

How to create Local Repositories in RHEL

I need to create a local repository in RHEl 5.5. i386 Because when I type some command in terminal it say that RHEL is not subscribed with RHN which is true. I took it from friend. So can someone ...
3
votes
1answer
818 views

Can't get past EFI to install RHEL on HP Itanium Server

When I am trying to install RHEL (6.3, 5.8, 4.8) on an HP Integrity Server rx2660 Itanium with 4GB RAM, I keep getting to the same point which is Loading file efi\boot\initrd.img...done After that ...
2
votes
3answers
5k views

Parallelise rsync using GNU Parallel

I have been using a rsync script to synchronize data at one host with the data at another host. The data has numerous small-sized files that contribute to almost 1.2TB. In order to sync those files, ...
2
votes
3answers
4k views

How to install Redhat using the iso image stored on Network

This is the case. I want to install the Redhat 5.6 on my system. But this time i dont want to use the actual DVD but this time i want to install it using the iso image stored on one of our server HDD. ...
1
vote
1answer
129 views

Apache can't access file while is has permission

I don't want to allow others read access, so I have added my user and the apache user to a group called apachme and then set that group to all the files and folders I want apache to have access to, ...
1
vote
3answers
8k views

Using nohup to keep a script running indefinitely

I am very new to Linux and I've only been using it to SSH to my web server using Putty. The issue I am having is this: Basically I've got 2 php scripts. One get_tweets.php constantly listens for ...
1
vote
1answer
2k views

RHEL Installation issue with UEFI on HP Compaq Desktop

I have bought a new Desktop HP Compaq Elite 8300 SFF. It came with Windows 7 Pro installed. Now I want to install Linux (RHEL) by dual booting it. I have successfully shrinked the partition and ...
1
vote
2answers
7k views

How to extend LVM in RHEL 5.6

I need to extend the LVM on one server. This is the output of df -h: Filesystem Size Used Avail Use% Mounted on /dev/cciss/c0d0p2 58G 26G 29G 48% / ...
1
vote
1answer
1k views

NIS and autofs error

I am trying to share the home directory of a NIS user using NFS and autofs. During testing, I get the following error message: Could not chdir to home directory /home/guest/nis1: Permission denied ...
0
votes
0answers
49 views

Incorrect keyboard mappings on RHEL v6.4

Spent a while trying to create keyboard shortcuts in terminal for command history access (up/down arrow keys). Realized after some frustration that this wasn't the issue - some keyboard keys are just ...
-1
votes
2answers
171 views

find and print file path, without filename

Please check the below awk '/SOURCE/ {print $3}' /MAC/Delete_Name.txt | while IFS= read -r file; do find /OS/ -iname "$file.pdf" ; done This results in output like this: ...
-1
votes
1answer
551 views

routing based on source IP [closed]

Is it possible to configure routing based on source ip? For example, if I have source IP 10.0.0.0, then all the traffic will go via the specific interface or would be sent to specific default gateway. ...
60
votes
7answers
26k 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, ...
14
votes
2answers
16k views

( /etc/sysconfig/iptables ) “Manual customization of this file is not recommended.” Why?

Editing this file directly /etc/sysconfig/iptables can save me so much headaches so much time and so on... and yet on the very top of the file it says.. Manual customization of this file is not ...
7
votes
3answers
28k views

How can I get TLSv1.2 support in Apache on RHEL6/CentOS/SL6?

I'd like to have TLSv1.2 support in Apache on my Scientific Linux 6 (RHEL6 rebuild) server. Is there some semi-supported pathway to getting this working? Preferably with minimal custom rebuilding. ...
18
votes
8answers
80k views

How to boot Linux to command-line mode instead of GUI?

I am using 32-bit Red Hat Linux in my VM. I want to boot it to command-line mode, not to GUI mode. I know that from there I can switch to GUI mode using startx command. How do I switch back to ...
28
votes
4answers
24k views

Why SSH takes a long time to Connect

I have noticed that some Linux Servers in Network takes long time to connect using ssh. Situations: There are two situations I have faced: On some servers some times it takes a long time to ask ...
11
votes
3answers
26k views

How to set global environment variables at boot through a script, and have them available for an application that runs before login?

I have a service that runs at boot, and in that service it calls a bash script in the background that exports some environment variables. The problem I'm having is that those environment variables ...