Hello Beautiful People !!!

[Dev Guy]

Hi Madi,

thank you for your input and welcoming me to the group =) .... I am feeling ignored and think maybe I should start up a thread off topic ;) ... the religion thread is getting a lot of participation, people love to share. I wish there was this much excitement about linux.

Maybe we can start a thread off topic about which gender is better next? or what race is more superior!

Rajinder




________________________________
From: Madison Kelly <linux-5ZoueyuiTZhBDgjK7y7TUQ at public.gmane.org>
To: tlug-lxSQFCZeNF4 at public.gmane.org
Sent: Thursday, April 9, 2009 7:14:32 PM
Subject: Re: [TLUG]: Hello Beautiful People !!!

Welcome to the list!

A topic I know others will raise; Please send email in plain-text format, not HTML. Several people here use text-only mail readers.

Dev Guy wrote:
> Wow my first day on the thread as a new member to the Linux group and we're debating the creator and religion!

GTALUG is a community. :)

> Hello everyone, great to be in the company of open minded passionate people! I've joined this group to develop a deeper understanding of Linux. I am a Slackware oldie but newbee, and currently CentOS has caught my attention!

Welcome back!

> I am here out of selfish reason to learn how to be a better Linux administrator with CentOS. I plan to use these skills to manage my website down the road.

Ultimately we're all here for the "selfish" reason of wanting help.

> What I need to figure out is how to use the capabilities of virtulization or maybe it's clustering to use multiplte servers at the software level to create a load-balanced environment? For example, creating a online group that will require more server overtime to accomodate the demand of increased traffic and increased storage. How could one go about getting this done?

You need to understand the differences between virtual servers and load balancing.

Virtual servers:

These are machine installed inside a virtualized environment like Xen, VMWare and so on. The major benefit of this is that the entire "machine" is really just a file. You can very easily back this up, move this between hardware machines and so forth. It is primarily a convenience thing. For example, when your underlying hardware no longer provides fast enough performance, you can build a new machine with new hardware and an updated OS and, when you are ready, simply copy the virtual machine's file over and start it up. No need to worry about all the wierd and esoteric changes you've made over the years.

Clustering:

This is done for one of two reasons; the first being for spreading the load out among multiple machines and the second is ensure your services are provided even when a given server blows up with little to no downtime. In either case, multiple virtual machines on one server will provide no such benefit.

> I plan to go with a host and start off with a single server and later add server as required. Is there a way for me to scale easily without the use of handware other than the servers?

Are you planning to run a custom written application? If so, it needs to be designed for some form of clustering and/or fail-over. If you are using a canned application, you will need to ensure that it supports the same or that it can be supported by something like heartbeat/HA-Linux.

> Is there any opensource software that will allow me to do this using a GUI tool on CentOS in particual?

Again, depends on what you want your cluster to do. In some cases though, yes. Look at: http:///ha-linux.org

> Thanks for your assistance in this matter and I hope I can contribute to the group as my skills develop.
> 
> Kind Regards,
> Rajinder Yadav

Something to keep in mind; Clustering introduces many new points of failure. They are something that need to be carefully studying and planned for. Specifically, is the added complexity and risk sufficiently offset by some benefit? Ask yourself; "Would a second spare server that periodically copies the changed files from the main server act as a sufficient spare?". Ask other similar questions.

In all cases, choose the simplest solution that addresses your needs and you will be a happy admin. :)

Madi
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists



      __________________________________________________________________
Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your favourite sites. Download it now
http://ca.toolbar.yahoo.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gtalug.org/pipermail/legacy/attachments/20090409/7c863780/attachment.html>