Friday, April 28, 2017

GlusterFS concepts and Architecture


I have made a presentation at GlusterFS meetup about GlusterFS - Concepts and Architecture:

You can access slides from here:
http://redhat.slides.com/sarumuga/glusterfs_concepts_arch?token=iTBb9tPy


For trying out GlusterFS in CentOS, you can use this:
https://wiki.centos.org/SpecialInterestGroup/Storage/gluster-Quickstart


You can join the meetup for gaining more knowledge about GlusterFS:
https://www.meetup.com/glusterfs-India/







Sunday, April 16, 2017

OpenShift origin installation issues and fix


==================================

# Add a entry for master node and slave nodes in /etc/hosts
192.168.122.152 m1
192.168.122.210    c2
192.168.122.144    c1

# setup OpenShift cluster
ansible-playbook byo/config.yml 


# faced this error
fatal: [m1]: FAILED! => {"changed": false, "cmd": ["oc", "create", "-n", "openshift", "-f", "/usr/share/openshift/examples/image-streams/image-streams-centos7.json"], "delta": "0:00:00.181546", "end": "2017-04-16 23:59:08.477861", "failed": true, "failed_when_result": true, "rc": 1, "start": "2017-04-16 23:59:08.296315", "stderr": "Unable to connect to the server: x509: certificate signed by unknown authority", "stdout": "", "stdout_lines": [], "warnings": []}

# check differences between these two files - there are few differences, especially master's IP vs hostname

vimdiff /etc/origin/master/admin.kubeconfig  /root/.kube/config

# remove kube config file
mv  /root/.kube/config  /tmp/

# setup OpenShift cluster again
ansible-playbook byo/config.yml 
----------------------------------------------------------------
PS:
1.
Another error faced is:

TASK [openshift_master : Start and enable master]
FAILED - RETRYING: TASK: openshift_master : Start and enable master (1 retries left).
fatal: [m1]: FAILED! => {"attempts": 1, "changed": false, "failed": true, "msg": "Unable to start service origin-master: Job for origin-master.service failed because the control process exited with error code. See \"systemctl status origin-master.service\" and \"journalctl -xe\" for details.\n"}


2. When verified using journalctl -xe, following is the error:
 http: TLS handshake error from 192.168.122.152:48958: read tcp4 192.168.122.152:8443->192.168.122.152:48958: read: connection reset by peer



----------------------------------------------------------------
All the issues can be resolved by removing /root/.kube/config and rebuilding cluster using ansible-playbook again.



==================================

References:
https://wiki.centos.org/SpecialInterestGroup/PaaS/OpenShift-Quickstart

https://www.clouda.ca/blog/general/openshift-on-centos-7-quick-installation/

Wednesday, April 5, 2017

reset your display size to normal


To set your screen resolution back to normal, use xrandr like this:

$ xrandr -s 0
The “-s” option allows you to specify the size, and the “0″ parameter tells xrandr to reset the screen to its default size

Tuesday, March 28, 2017

Android storage access in PC - usb detection issues in Redmi Note



Redmi Note had some issue in getting detected in PC (while connecting via USB).


This app helped:

MIUI USB Settings
https://play.google.com/store/apps/details?id=co.vincze.usbsettings



First ensure, USB debugging is enabled.

You need to go to additional settings -> Developer options[1] -> USB debugging.

Then Open this app and enable MTP.

Now, Android storage should be available in PC.


[1]
For getting Developer options, you need to click on MIUI version few times. (It will display how many times to click to get Developer options enabled).

yaml format

YAML is a markup language with many powerful features

Rule 1:
YAML uses a fixed indentation scheme to represent relationships between data layers. 
Each level consists of exactly two spaces. DO NOT USE TABS.

Rule 2:
colons:

key value pair using colon.

my_key: my_value

my_key:
  my_value

Rule 3:
Dashes

list of items
- list_value_one
- list_value_two
- list_value_three


For existing files, You can convert tabs to 2 spaces by these commands in Vim::set tabstop=2 expandtab and then :retab.

The suggested syntax for YAML files is to use 2 spaces for indentation,
https://docs.saltstack.com/en/latest/topics/yaml/index.html

source: https://docs.saltstack.com/en/latest/topics/yaml/index.html