Install Cassandra 3.9 on CentOS 6.8

Install Cassandra 3.9 on CentOS 6.8

Install Java 8

$  yum install java-1.8.0-openjdk

Add DataStax Repo for Apache Cassandra

$  vi /etc/yum.repos.d/datastax.repo

Add the following lines to the new file:

[datastax-ddc] name = DataStax Repo for Apache Cassandra baseurl = enabled = 1 gpgcheck = 0

Save the file above and run:

$  yum […]

Apache Cassandra Centos 7

Apache Cassandra is a NoSQL database intended for storing large amounts of data in a decentralized, highly available cluster. Cassandra or Apache Cassandra is a distributed database system which manages large amounts of structured data across different commodity servers by providing highly available service with no point of failure. NoSQL refers to a database with […]

Oracle ASM 12c on Linux

How to setup Oracle ASM 12c on Linux Software used:- 1.VMWARE 10 2.Redhat enterprise linux 6.5(64 bit) 3.Oracle database 12C (64 bit) 4.Oracle Grid infrastructure 12c(64 bit)

What to Setup:-

1. Setup oracle grid infrastructure for standalone server “ASM” 2. Setup oracle Database

Update /etc/sysctl.conf [root@server1]# vi /etc/sysctl.conf Scroll to the bottom and add the […]

grubby fatal error: unable to find a suitable template

grubby fatal error: unable to find a suitable template

Updating   : selinux-policy-3.7.19-292.el6_8.3.noarch                                                                                                             8/28 Updating   : selinux-policy-targeted-3.7.19-292.el6_8.3.noarch                                                                                                    9/28 Installing : kernel-2.6.32-642.15.1.el6.x86_64                                                                                                                   10/28 grubby fatal error: unable to find a suitable template Updating   : ntp-4.2.6p5-10.el6.centos.2.x86_64                                                                                                                  11/28 Updating   : libtiff-3.9.4-21.el6_8.x86_64                                                                                                                       12/28 Updating   : kernel-headers-2.6.32-642.15.1.el6.x86_64                                                                                                           13/28 Updating   : tzdata-2017a-1.el6.noarch                                                                                                                           14/28 Cleanup    : kernel-2.6.32-573.26.1.el6.x86_64                                                                                                                   15/28 warning:    erase unlink of /lib/modules/2.6.32-573.26.1.el6.x86_64/weak-updates […]

DOCKER Testing

Obtaining the Docker image

First, get the basic Docker image. The Docker image is published on the Docker Hub Registry ( You can search for published images with the docker search command. An example of searching the image of CentOS is here.

# docker search centos

INDEX       NAME                                      DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED                          The […]

Docker Centos 7


vim  /etc/default/docker


docker-images     docker     docker

[root@docker-images ~]# cat /etc/RedHat-release CentOS Linux release 7.2.1511 (Core) [root@docker-images ~]# uname -r 3.10.0-327.el7.x86_64 [root@docker-images ~]# uname -m x86_64 [root@docker-images ~]# uname -a Linux docker-images 3.10.0-327.el7.x86_64 #1 SMP Thu Nov 19 22:10:57 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux [root@docker-images ~]#


[root@docker-images […]

sshd debug

1. To run sshd in debug mode as a one time instance without affecting other users: # /usr/sbin/sshd -ddd -D -p (port) 2>&1 | awk ‘{ print strftime(“%T: “), $0; fflush(); }’ | tee sshd.log 2. On the client end run add -p (port) to the ssh command line # ssh -p (port)



Disable Password Authentication for SSH

How to Disable Password Authentication for SSH

Once you have SSH Keys configured, you can add some extra security to your server by disabling password authentication for SSH. (Note that if you do lose your private key, this will make the server inaccessible and you will need to contact HostGator to have this re-enabled.)

To […]

active directory ssh authentication

Here is my configs and setups: /etc/nsswitch.conf

passwd: compat winbind shadow: compat winbind group: compat winbind #hosts: db files nisplus nis dns hosts: files dns bootparams: nisplus [NOTFOUND=return] files ethers: files netmasks: files networks: files protocols: files rpc: files services: files netgroup: files publickey: nisplus automount: files aliases: files nisplus

/etc/pam.d/system-auth (generated via the “setup” […]

tomcat 32 bit Could not reserve enough space for 1048576KB object heap

 Commons Daemon procrun stdout initialized

Error occurred during initialization of VM

Could not reserve enough space for 1048576KB object heap


Here is how to fix it: Go to Start->Control Panel->System->Advanced(tab)->Environment Variables->System

Variables->New: Variable name: _JAVA_OPTIONS Variable value: -Xmx512M

Variable name: Path Variable value: ;C:\Program Files\Java\jre6\bin;F:\JDK\bin;

Change this to your appropriate path.



Page 1 of 41234