In this post we will go thru all the required Prerequisite that need to be done before installation.
1- Install Linux using a minimum server configuration.
2- Allocate swap space
allocate 2GB or more of swap space independent on the RAM size.
Guidelines for CentOS/RedHat swap space are as follows:
4GB of RAM requires a minimum of 2GB of swap space
4GB to 16GB RAM requires a minimum of 4GB of swap space
16GB to 64GB of RAM requires a minimum of 8GB of swap space
64GB to 256GB of RAM requires a minimum of 16GB of swap space
To find the current swap space alocated:
To add the 2GB or more of swap use the following commands:
the command will add a 2GB swap file mounted on "/newswap" partition
3- Disable CPU frequency scaling
Stop the service:
Disable at boot time:
Add the swap file to the system in real-time:
Finally, modify the /etc/fstab to automatically add the new swap at system boot time by adding the following line:
4-Configure the I/O Scheduler
Why do you need to do this ?
Well Vertica is a very needs read requests over write requests. By deafult Linux configuration comes with the
CFQ(Completely Fair Queuing?levator=cfq (default)) scheduler enabled which is an overall good use
To alter the Scheduler you need to do it for all the devices that are to be used in Vertica configuration.
The brackets represents the mode that will be used by the partition.
To change the scheduler, write the name of the scheduler you want the device to use to its scheduler file.
You must have root privileges to write to this file.Changing the scheduler immediately affects the I/O requests for the device.
Create a file called setscheduler.sh in /etc/init.d/ and add the following content:
Make the file executable:
Register it as an init.d script:
5-Prepare disk storage locations
In a Vertica cluster configuration the data locations must reside in the same paths on all nodes. Always mentain the data separete from the catalog.
Before installing the database make sure that data in catalog locations are created on all nodes and owned by the database administrator.
Vertica requires aditional disk space for several internal operations, so it is recomanded that no more then 60% of the disk
should be used by data leaving space for the internal operations to take place.
6-Allow passwordless SSH access for dbadmin
Verify that sudo is available on all cluster hosts
The dbadmin user must have authorization for passwordless ssh. In typical installs,
you do not need to make any changes. However, if you have set up your system to
disallow passwordless login, then you must enable it for the dbadmin user. To enable
passwordless ssh access for the dbadmin user, edit the /etc/sudoers file and add this line:
7-Alter the pam_limits.so file.
8-Set the time zone on the cluster nodes:
You can set the time zone several different ways, depending on the Linux distribution or the system administrators' preferences.
To set the system time zone edit:
To set the TZ variable, edit /etc/profile or /root/.bashrc and add the following line:
8-Set host locale (language)
For this task you need to edit the file /home/dbadmin/.profile on all cluster nodes and add the follwoing line :
LANG determines the locale category for native language, local customs, and coded character set in
the absence of the LC_ALL and other LC_ environment variables.
LANG can be used by applications to determine which language to use for error
messages and instructions, collating sequences, date formats, and so forth.
9-Check NTP daemon status:
The ntpd program is an operating system daemon which sets and maintains the system time of day in synchronism with Internet standard time servers.
To check if your hosts are configured to run the NTP daemon on startup:
If the NTP daemon is installed, output should resemble the following:
How to enable the ntp daemon :
10-Install the prerequisite for Vertica Cluster
rsync - rsync is a file transfer program for Unix systems. rsync uses the 'rsync algorithm' which provides a very fast method for bringing remote files into sync.
Configuring the Network
11-Configure host name resolution
Set the HOSTNAME environment variable
To do this follow the steps bellow:
1-Edit the files /etc/profile or /etc/bashrc and add the following lines:
2-Edit the /etc/sysconfig/network file to set HOSTNAME by adding the line:
Set up the /etc/hosts file on each node in the cluster.
Make sure that the /etc/hosts file includes all of the hosts that become part of the cluster. For example, if the hosts are named node01, node02, node03, and node04, the /etc/hosts file on each host looks like this:
All private interfaces should be on the same subnet and have the same broadcast address.
Disable SELinux after install SELINUX=enforcing to SELINUX=disabled
To disable edit the /etc/seLinux/config file .
Take out the firewall rules form the startup tasks:
Stop the filewall rules:
13-Provide root and SSH access to the cluster
Make sure that root user has acess to all hosts without using password via ssh.
14-Ensure that port 5433 is not in use and that /dev/pts is mounted.
15-Install the following before installing the Cluster
Perl must be installed.
Python must be installed.
Vertica supports the ext3 and ext4 file systems.
Linux Logical Volume Manager (LVM) is not supported.
Recommended disk block size is 4096 bytes.
After all of this are done reboot your hosts and after this you can start installing the cluster.