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[ipv4]
address1=10.10.10.29/24,10.10.10.1
dns=10.10.100.12;10.10.100.13;
dns-search=ocp.example.com
method=manual

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### One of the MCP degraded, machine-config-daemon show error log : expected target osImageURL
### Pause of the update procedure (in console), then on the degraded node:

# ssh core@degraded-node
# sudo -i
# rpm-ostree rollback 
# systemctl reboot

### After the node is up again, force the node to re-pull the image and extract the osImage :

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### Create file called machine-config-daemon-force in /run ###
ssh core@hostname.local sudo touch /run/machine-config-daemon-force

### Edit node annotations ###
oc edit node <node-name>

### Check Annotations, change like below sample ###
 machineconfiguration.openshift.io/currentConfig: rendered-worker-ab4a1e7216bf3da2a5203f09c871b456
 machineconfiguration.openshift.io/desiredConfig: rendered-worker-ab4a1e7216bf3da2a5203f09c871b456
 machineconfiguration.openshift.io/reason: ""

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### Install few required packages to run SNX
sudo dnf install -y java-1.8.0-openjdk.x86_64 icedtea-web.x86_64 libstdc++.i686 libX11.i686 libpamtest.i686 libnsl.i686

### Download compat-libstdc++ driver and install it
wget http://mirror.centos.org/centos/7/os/x86_64/Packages/compat-libstdc++-33-3.2.3-72.el7.i686.rpm
sudo dnf -y install compat-libstdc++-33-3.2.3-72.el7.i686.rpm

### Install snx_linux.sh
### Download snx_linux_30.sh file from Checkpoint
### Active URL : https://supportcenter.checkpoint.com/supportcenter/portal/user/anon/page/default.psml/media-type/html?action=portlets.DCFileAction&eventSubmit_doGetdcdetails&fileid=22824

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# It's not recommended to change the active running OCP Master nodes IP Properties unless it's really required to be done.
# To do that, please follow below guide :

# 1. Update the DNS server to use new IP for the target master nodes
# 2. Change the node IP Address from "nmcli" or "nmtui", and reboot the server
# 3. Post reboot, the existing will act normally, but somehow, etcd is not in healthy state. Re-add the etcd member will solve
# 4. Check which etcd pods is CLBO 

oc project openshift-etcd
oc get pods -l k8s-app=etcd

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###Data Collection for Red Hat Threescale
$ oc adm must-gather --image=quay.io/3scale/must-gather

###Data Collection Audit logs
$ oc adm must-gather -- /usr/bin/gather_audit_logs

#It's also possible to generate the default must-gather including the audit logs:
$ oc adm must-gather -- '/usr/bin/gather && /usr/bin/gather_audit_logs'
#Also see https://access.redhat.com/solutions/5373481

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Red Hat Internal KB : 
https://access.redhat.com/solutions/7023254?band=se&seSessionId=522ca7b0-a002-43d3-a5d2-9a7e387186c0&seSource=Recommendation&seResourceOriginID=09abffc5-23dc-465e-a013-9e52e91306cf

Openshift 4.8 below doesn't have auto rotation for etcd certificate and it will be expired within 3 years

High Level steps :
1) Copy etcd-signer and etcd-metric-signer CA from etcd DB to some folder, create the crt and key file for each signer
2) Backup all manifests for static pods in each master
3) Backup all existing etcd certificates inside /etc/kubernetes/static-pod-resources/etcd-certs/secrets/
4) Create new folder inside above folder ie. call as "all-certs", copy all certificate inside secrets folder to the "all-certs" folder

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###The workaround consist on modifying the settings to accept the internal hostname. The steps are the following:

###Copy the settings.yml file from system-app:
oc rsh -c system-provider dc/system-app cat /opt/system/config/settings.yml > settings.yml

###Edit the field apicast_internal_host_regexp from
#    '\Asystem-(master|provider|developer)\Z'
#    to
#    '\Asystem-(master|developer|provider)(\.(.*)(\.svc\.cluster\.local))?\Z'

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### Openshift Summarized KB ###
https://access.redhat.com/node/5218861

### PipelineRun takes a lot of time to get started on OpenShift Container Platform 4 ###
https://access.redhat.com/solutions/7005157

### Cluster Updates Without Error but Machine Config Pools Degraded with `Marking Degraded due to: unexpected on-disk state` on 4.6 and newer
https://access.redhat.com/solutions/5598401

### How to Use 'fio' to Check Etcd Disk Performance in OCP

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### Removal from RHV Manager UI is not possible anymore, remove button has been greyed out
# SSH to RHV Manager hosts
su - postgres
psql -d engine
SELECT vds_id FROM vds_static WHERE vds_name = 'hostname of the unresponsive hosts';
# Capture the vds_id
DELETE FROM vds_dynamic WHERE vds_id = 'vds_id of the unresponsive hosts';
DELETE FROM vds_statistics WHERE vds_id = 'vds_id of the unresponsive hosts';
DELETE FROM vds_static WHERE vds_name = 'hostname of the unresponsive hosts';