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29 votes
Accepted

Limit the RAM available to RHEL8

Boot with the kernel parameter mem=32G: mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory Amount of memory to be used when the kernel is not able to see the whole system memory or ...
vidarlo's user avatar
  • 8,937
26 votes

Newly created XFS filesystem shows 78 GB used

All filesystems have an overhead for their own internal data structures. This internal information is used for the filesystem to create files and directories in future, and to keep track of where ...
Moshe Katz's user avatar
  • 3,162
10 votes
Accepted

How to disable Web Console and Red Hat Insights prompt on login to RHEL8 via SSH?

I figured it out before I finished writing this question so I figured I'd just share this with anyone else. # ls /etc/motd.d -lh total 0 lrwxrwxrwx. 1 root root 17 Mar 12 19:46 cockpit -> /run/...
cyqsimon's user avatar
  • 335
9 votes
Accepted

Why the RHEL8 system do not generate SSH host keys automatically when missing?

The sshd service by default calls sshd-keygen.target, which checks availability of host keys in /etc/ssh directory and generates it when missing. However this well known functionality can be blocked ...
Jaroslav Kucera's user avatar
8 votes
Accepted

Newly created XFS filesystem shows 78 GB used

For XFS, the empty filesystem "Size Used" as shown by df -h seems to depend a lot on which metadata features you enable at mkfs.xfs time. Testing with an empty 12TB file: # truncate -s 12TB xfstest....
frostschutz's user avatar
8 votes

Is there a good way to allow non-root users to mount arbitrary external USB drives on Linux?

You could use udisks2, which allows users to manage and mount storage devices without root access. Setup Install the tool: sudo dnf install udisks2 ntfs-3g fuse-exfat Allow user to manage: sudo ...
Saxtheowl's user avatar
  • 1,162
6 votes

Yum on Centos 8 - Failed to download metadata for repo 'AppStream'

Apparently not the problem here, but if you have pinned yourself to CentOS 8.1.1911 you will get the same error until you re-point your /etc/yum.repos.d/ repositories at http://vault.centos.org ...
Raven's user avatar
  • 161
6 votes

RHEL 9 in Docker container on macOS: subscription-manager is disabled when running inside a container

All you need is just a return False from in_container(), See https://github.com/candlepin/subscription-manager/blob/subscription-manager-1.28.32-1/src/rhsm/config.py#L105-L114: FROM registry.access....
Wong Hoi Sing Edison's user avatar
5 votes
Accepted

"system clock synchronized: no", flip it to yes

chronyc sources indicates that it does not have connectivity to any of the available NTP servers. This is what the ? in the S column means, from the man page: This column indicates the state of the ...
Michael Hampton's user avatar
5 votes
Accepted

New to RHEL; Coming from Fedora; Different repo managers?

RHEL itself doesn't ship a large number of packages; only those they can provide professional support for. A large number of additional packages you may be looking for are in the EPEL (Extra Packages ...
Michael Hampton's user avatar
5 votes

Limit the RAM available to RHEL8

Yes, you can allocate a fixed amount of RAM for testing purposes on a server with more physical RAM than you need. To do this, you can use control groups (cgroups) in Red Hat Enterprise Linux (RHEL) ...
4 votes

Unable to install RHEL 8 on older hardware

RHEL 8 dropped support for a lot of ancient hardware. Since ancient hardware is what you are using, you should not be too surprised that it doesn't work. Your computer is from 2008 and even the "...
Michael Hampton's user avatar
4 votes
Accepted

GSSAPI Error: KDC has no support for encryption type on RHEL 8 joined to multi-domain AD forest

The properties of an AD trust include a property called "The other domain supports Kerberos AES Encryption". By default, this option is not checked. In this scenario, this leads to the fact, ...
stackprotector's user avatar
4 votes

Change certbot renewal configurations to another Let’s Encrypt-Account

I had the same/similar question and was not able to find a good answer (I have multiple accounts across different servers). In the end I decided to rather simply change the email address for the ...
maltem-za's user avatar
  • 141
4 votes

Dell PowerVault TL1000 Tape Library RHEL 8 Connectivity

You may install Starwinds tape redirector on the Windows host with a tape library. Tape redirector is able to share it over iSCSI into the RHEL VM. The job is done :) https://www.starwindsoftware.com/...
Stuka's user avatar
  • 5,680
3 votes

Yum on Centos 8 - Failed to download metadata for repo 'AppStream'

In the name of ALLAH. I think that This problem reseon is for End of Life of centos version.. CentOS Linux 7 EOL: 2024-06-30 CentOS Linux 8 EOL: 2021-12-31 CentOS Stream 8 EOL: 2024-05-31 CentOS ...
ahmadzadeh110's user avatar
3 votes

Yum on Centos 8 - Failed to download metadata for repo 'AppStream'

You need to be connected to the Internet in order to download packages. Check that you have an IP address (with ip a), that you have a default route (with ip r), and that you have nameservers defined ...
Michael Hampton's user avatar
3 votes

Should I install RHEL8 or RHEL7?

There is an epel-release for RHEL 8, which you can install now. But there are very few packages right now, as EPEL is having to be rearchitected significantly for RHEL's new AppStream packaging system....
Michael Hampton's user avatar
3 votes

RHEL8: Does NFS I/O count as part of "%iowait" calculations?

Yes, on Linux, NFS is included in iowait time, and contributes to the load average. Red Hat KB Does NFS cient I/O count iowait% on linux? shows packet loss to an NFS server increasing iowait. ...
John Mahowald's user avatar
3 votes
Accepted

Kubeadm with containerd cannot use locally loaded images

It turned out that I had to load images to the k8s.io namespace of the containerd so that Kubernetes can recognize them. I was importing the images to the wrong namespace (default). ctr -n k8s.io ...
Daigo's user avatar
  • 393
3 votes

Why the RHEL8 system do not generate SSH host keys automatically when missing?

If you are using cloud-init, then you can fix it by adding 'ssh' module in cloud-init config file in section "cloud_init_modules". Refer cloud-init docs This will generate ssh host key ...
Arun S's user avatar
  • 31
2 votes

Install Certbot in Red Hat Enterprise Linux 8 manually

Certbot is fully supported under RHEL/CentOS 8 now. Just run wget https://dl.eff.org/certbot-auto chmod +x certbot-auto For apache ./certbot-auto --apache For nginx ./certbot-auto --nginx It ...
Pozzo-Balbi's user avatar
2 votes

ImportError: No module named svn.core Python Traceback

As RedHat don't provide Subversion SWIG Python bindings package[1] which is needed for ViewVC Subversion support, you need 3rd party package[2], such as Collabnet or WANdisco, or build it from source. ...
futatuki's user avatar
2 votes
Accepted

Increasing ulimit open files not applied in RHEL 8.1

In a systemd setup before version 240 all user processes run under default user resource limits suggested by the kernel, which on RHEL 8.1 appears to be 4096 for the hard limit and 1024 for the soft ...
Gerrit's user avatar
  • 1,572
2 votes
Accepted

How to install Node.js 12 on CentOS 8?

yum module enable nodejs:12 yum install @nodejs:12/common Taken from here: https://docs.centos.org/en-US/8-docs/managing-userspace-components/assembly_installing-rhel-8-content/
NStorm's user avatar
  • 1,342
2 votes

Partitioning/RAID approach for a fresh RHEL installation

R1 mirror of the 2 x 300GB as your OS/boot/root drive then a R10 or R6 of the 6 x 600GB for data, which you choose depends on whether you need the 1.1TB of slower space of R6 or the 850GB of faster ...
Chopper3's user avatar
  • 102k
2 votes

How to restrict users switching from su command

As you know, root user is the conventional name of the user who has all rights or permissions (to all files and programs) in all modes (single- or multi-user). The root user can do many things an ...
Alejandro F.'s user avatar
2 votes
Accepted

Create selinux context for systemd script?

Move your script out of the user's home directory. SELinux rightly complains about trying to execute system services located in users' home directories. Use a more standard location, such as /usr/...
Michael Hampton's user avatar
2 votes

Expecting a password in the middle of script in RHEL

sshpass is available from EPEL repository. Technically not a part of CentOS, but easy to enable if you wish. Passwords are insecure, consider any other method of ssh auth instead. sshpass's reason for ...
John Mahowald's user avatar
2 votes

Using variable lists in ansible returns undefined variable

TL;DR loop: "{{ stuff }}" Full story On the contrary of the former and still widely defaulty used with_items:, a bare loop: does not apply an automatic flatten(level=1) on the passed ...
Zeitounator's user avatar
  • 1,283

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