Run the following command to calculate the currently used memory (megabytes) in openshift container platform 4.x. oc adm top node | awk '{ sum+=$4} END {print sum}' Run the following command to calculate the used memory (megabytes) for worker nodes in the cluster. oc adm top node --selector='node-role.kubernetes.io/worker=' | awk '{ sum+=$4} END {print sum}' …
Why repquota output different size as compared to du?
In CentOS 5, 6, and 7, repquota shows different sizes compared to du output as shown below. [root@server]# repquota /xyz | awk 'NR == 3 || NR == 4|| /username/' Block limits File limits User used soft hard grace used soft hard grace username -- 100663296 152043520 157286400 2584811 0 0 [root@server]# du -sch /xyz …
How do change the location of /var/log/squid/squid.out file?
To change the location of squid.out file, copy /usr/libexec/squid/cache_swap.sh to a new location. # cp /usr/libexec/squid/cache_swap.sh /usr/libexec/squid/cust_cache_swap.sh Open with vi and edit the following section in the new file cust_cache_swap.sh. squid -N -z -F -f $SQUID_CONF >> /new/path/to/squid.out 2>&1 Copy the unit file of squid.service as follows. # cp /usr/lib/systemd/system/squid.service /etc/systemd/system/ Edit /etc/systemd/system/squid.service. (before) ExecStartPre=/usr/libexec/squid/cache_swap.sh …
Why packets drops against ‘rx_fifo_errors’ parameter in the output of ‘ethtool -S ‘ ?
The output of ethtool -S <interface> reveals receive fifo errors. Additionally, rx_queue_<n>_drops, the total of which equals the value of rx_fifo_errors, are reported. # ethtool -S eth0 | egrep 'rx_fifo|drops' rx_fifo_errors: 120674 rx_queue_0_drops: 4032 rx_queue_1_drops: 3036 rx_queue_2_drops: 5904 rx_queue_3_drops: 0 rx_queue_4_drops: 228 rx_queue_5_drops: 65656 rx_queue_6_drops: 19267 rx_queue_7_drops: 22551 # ethtool -S eth0 | egrep drops …
lsof does not list as many files with -p as when used with grep and awk
Only files opened by the specified PID are listed using the lsof command with the -p option.The -p option entirely ignores files generated by a thread with a TID. When we grep for a specific PID, it lists all the lines where the PID is located while considering the files opened by a thread. The …
How to hide processes from other users in ps and top in CentOS Server?
The hidepid option in RHEL has the value 0 by default. This implies that all data is visible to every user. The directory entries in /proc will remain visible but inaccessible when set to 1.To keep the data hidden from /proc, set the value to 2. Run the following command to instantly apply the changes. …
Why Ansible Engine / Tower job fail with ‘Server not found in Kerberos database’ Error ?
My playbook job fails with the error “Server not found in Kerberos database” when executed against a Windows server with Kerberos authentication. TASK [Ping host] ****************************************************************************************************************************************************************************************** fatal: [host01.mydomain.com]: UNREACHABLE! => {"changed": false, "msg": "kerberos: authGSSClientStep() failed: (('Unspecified GSS failure. Minor code may provide more information', 851968), ('Server not found in Kerberos database', -1765328377))", "unreachable": true} …
How to test playbook on Ansible Tower nodes from the command line
Login to the Ansible Tower node and change to awx user. # sudo su -awx If you use a custom virtual environment in Ansible Tower, source it as follows. source /var/lib/awx/venv/ansible/bin/activate For Ansible or your custom virtual environment, export the Python path used during Ansible Tower task executions. On the CentOS 7 Server, run as …
PostgreSQL versions supported by Ansible Tower and Ansible Automation Platform?
On docs.ansible.com, you can find the prerequisites for each Red Hat Ansible Tower and Red Hat Ansible Automation Platform version. Specific Red Hat Ansible Tower and Red Hat Ansible Automation Platform version requirements can be viewed by adjusting the versions in the documents section at the top left of the URL above. Ansible Tower/Controller Version …
How to install and use Ansible collections from Ansible Galaxy having no internet access?
Download the relevant collections’ tarballs from Automation Hub or Ansible Galaxy on a system connected to the internet. You must now do the following actions on each of the Tower nodes: Make a directory for collections, like /opt/collections/ # mkdir /opt/collections/ Change the file’s permissions and group ownership for the sei user as follows. # …
How to upgrade or update Ansible without upgrading Ansible Tower?
Users can upgrade the Ansible version without also upgrading Ansible Tower. Ansible should function well with Tower after being updated to the desired version using package manager (not pip), yum, or apt. When executed from the source, the most recent stable Ansible version is the only version Ansible Tower supports. Ansible cannot be installed using …
How to deactivate Ansible Tower/Automation Platform license/subscription?
You can initiate DELETE /api/v2/config/ API to deactivate Ansible tower or automation platform subscription. The command to deactivate is given below. $ curl -X DELETE https://<MY_ANSIBLE_TOWER_URL>/api/v2/config/ -u admin -kEnter host password for user 'admin': <password for admin user>
Failed to create notification semaphore: Invalid argument – LVM error
lvcreate gives the following error about semaphore. lvcreate -n test_lv10 -L 1G test_vg_3 Found duplicate PV XfbmuZ2c2MPAb8r0TDIBNrcyUx0yMZpu: using /dev/emcpowerh not /dev/sdb Failed to create notification semaphore: Invalid argument Unable to resume test_vg_3-test_lv10 (253:3) Failed to activate new LV. Failed to create notification semaphore: Invalid argument Unable to deactivate test_vg_3-test_lv10 (253:3) Unable to deactivate failed new …
How to create LVM snapshot for system maintenance?
This article shows step-by-step instructions for getting a CentOS system ready and making LVM snapshots for system maintenance or software upgrades. LVM snapshots are meant to be used as a restoration point if anything goes wrong during the upgrade process. The suggestion is to run this procedure in a test environment first. Also, one of …
How to shrink an LVM Logical Volume
Since shrinking is not supported on these file systems, you cannot reduce the size of a logical volume that houses a GFS2 or XFS file system. The lvreduce command typically warns about potential data loss and requests confirmation. In some circumstances, such as when the logical volume is inactive, or the —resizefs option is not …
