The musings of an IT Consultant

May 31, 2009  7:34 PM

New version of ghettoVCB out!

Raj Perumal Raj Perumal Profile: Raj Perumal

So my favourite script has a new version out! William Lam’s ghettoVCB script is now called ghettoVCBg2 and it’s bigger and better than ever!

He has come out with a new script that works with version vSphere version 4 without the need for the SSH console. He’s also added a lot of new features such as logging support and VM snapshot memory and quiesce options!

I am currently using this script testing it in my test lab environment and will write a detailed setup for you guys on how to setup the script in your new ESXi 4.0 enviornment. Now with VMware’s move to using VIMA for management everyone should start getting used to doing things this way as the rumor is that VMware will move away from having a normal console and move towards using the VIMA model for management in the future.  Stay tuned for more information on how to setup the new version of this script.

In the meantime if you can’t wait and want to give it a whirl on your own, you can grab it from the VMware communities here and give it a try!


May 31, 2009  7:26 PM

Upgrade ESXi 3.5 to ESXi 4.0 without vCenter

Raj Perumal Raj Perumal Profile: Raj Perumal

So ESXi 4.0 is now available and you want to get cracking learning everything you can about it. You go to upgrade it in your home environment or your test lab and you realize you can’t do anything because you don’t have vCenter. What do you do?

Never fear! You can upgrade it anyway! What’s the secret? The vSphere host update utility! You can gain access to it by downloading the vSphere upgrade zip file from the VMware website first and then extracting it using the program 7zip. 7zip will allow you to drill down into the following path: VMware-viclient.vib\data.tar.gz\data.tar\.\4.0.0\client\VMware-viclient.exe to extract the VMware client install file to install the vSphere client.

Once you install the client it will ask you to install the host update utility and then after that is done you can just launch the utility. Point it at your server and tell it to upgrade after putting your ESXi host in maintenance mode and presto, your ESXi server has been upgrade to 4.0. As per usual I always recommend you do backups before you attempt any upgrading or patching.

There is detailed instructions with screenshots you can follow here.


May 31, 2009  7:17 PM

Time to start planning for 10 GbE networks

Raj Perumal Raj Perumal Profile: Raj Perumal

So in this day and age 10 GbE switches are starting to become more popular. Recently many 10 GbE offerings have been announced from various vendors. This has got me thinking. Taking a quick survey of networks I have come across, there is still a huge proliferation of 10/100 and people are still starting to embrace 1 Gbps.

I think network admins, or whomever is responsible for their budgets need to loosen the purse strings a bit and let us network guys upgrade our network to handle the proliferation of high bandwidth applications out there now. We live in a media enriched world and more and more each day we are getting inundated with tons of large media content. If we don’t have the networks to support a constant stream of data we are going to fall behind.

At this point in time with the cheap cost of gig, I see no reason why every network shouldn’t be gigabit throughout and then 10 GbE through the major backbone connections of your internal network. Especially with virtualization here now, we are going to need those pipes to push all that data through. The next time you’re looking at network upgrades I urge you to look at your network and seriously think about upgrading from 10/100 to at least a gig.


May 31, 2009  7:10 PM

Implementing Location Awareness in your Organization

Raj Perumal Raj Perumal Profile: Raj Perumal

Hi folks, so if there is one thing that is annoying it’s misplacing things. Whether it’s some sort of important customer inventory, or whether it’s a piece of hardware you own and you need to know it’s whereabouts. What do people do in large organizations where you need to keep track of things?

Location awareness! In this day and age of wireless, there should be a technology out there that can be leveraged to help us with this and there is. Using RFID you can tag valuable mobile equipment or product and then use a device to keep track of where that stuff is in your organization.

Cisco has a product called the Cisco Wireless Location Appliance that does just this and fits into the grand scheme of their Cisco Unified Wireless Network. Something like this would be deployed in an environment with wireless controllers and managed lightweight APs across your network. I have a feeling we’ll be seeing more of a need for these kind of things as mobile devices and our need to keep track of them becomes more prevalent in the years to come. You can read more about this here.


May 26, 2009  4:18 PM

Configuring UPS Server Shutdown in your network environment

Raj Perumal Raj Perumal Profile: Raj Perumal

One thing I’d like to add to my previous post regarding UPS’. The other thing that is consistently seen out there in the IT world is not only administrators forgetting to change out expired batteries, but also administrators not configuring UPS’ to shutdown their servers properly.

Most UPS’ come with a serial port, usb or network connector and some sort of free software agent. This software agent can be installed on your servers and when the UPS detects a power outage you can configure the software to shutdown your server gracefully after a pre-determined amount of time.

All to often this software is completely left out of the loop in a server configuration or even still the administrator forgets to even connect the UPS monitoring cable to the server. This is just sloppy work in my opinion and it really should be done.

Some administrators have mentioned that they don’t configure UPS shutdown because with virtualization they have no idea how to configure this. If you go to the VMware communities you can find many scripts that show you how to configure UPS shutdown in a virtual environment.

-Cheers, RP

May 26, 2009  4:13 PM

Replacing UPS Batteries on a timely basis

Raj Perumal Raj Perumal Profile: Raj Perumal

So when asking clients about the most important things in their server room you will consistently hear answers about the speed and power of their network, or the latest loaded server they have. Perhaps they will even talk about the great things they’ve done with virtualization.

However, the one thing that people never seem to mention is their UPS power. The funny thing is without your UPS’, nothing would be running in the first place. Funnily enough, this is the one place people seem to consistently neglect in my experience.

You see UPS batteries should be replaced at least every 3 years otherwise they tend to get old and not perform as well as you’d expect them to. Instead you see people leaving in batteries for over 5 years with no replacement. At this point the batteries provide no backup power and they’re all but useless.

So the next time you are thinking about keeping your server room up to snuff, please make sure that your UPS batteries are replaced on a regular basis before they expire.


May 25, 2009  12:43 AM

Where to go for good wireless info

Raj Perumal Raj Perumal Profile: Raj Perumal

So I’ve often been asked where to go for good wireless info when you’re starting to learn the wireless trade as it relates to IT. This isn’t one of those things every tech out there knows how to do aside from the home based wireless routers available in your local electronics retailers.

There are a few certifications out there that stand out to me. One is the CCNA Wireless specialty certification from Cisco. The Cisco material does a good job of covering all the basics and also outlining their own product line of course. This isn’t necessarily a bad thing because Cisco is one of the major players in the wireless business.

Now if vendor neutral certs are more you style then I would steer you in the direction of the Wireless # certification. This exam however is retiring this year in July and will be replaced by the CWTS certification. After doing this there are a few other certifications you can go on to do to become more versed in the wireless world.

Another good idea is to get a lot of hands on experience with the equipment you learn about with these certs. You can do that by working for a company that does a lot of these wireless implementations. The combination of experience and certifications should make you a force to be reckoned with in the wireless world!


May 25, 2009  12:37 AM

Racking HP BladeSystems

Raj Perumal Raj Perumal Profile: Raj Perumal

One of the things I’ve seen a lot of is improper racking of HP BladeSystems. Sometimes people don’t take the time to RTFM and end up putting the whole thing together wrong in the rack. You’d think this wouldn’t be possible but it’s not that hard to do.

Two major things stand out wrong when racking an HP BladeSystem.

  1. People try and rack the HP BladeSystem while it’s fully populated with blades and interconnects and weighs well over a few hundred pounds. This is the quickest way to destroying your blade chassis by dropping it on the floor.
  2. After the blade is racked, people just put interconnects into any bay they want in the back without paying any regard to how the bays map to the mezzanine slots on the blades themselves.

What are the answers to these issues? Simple. For #1, you should completely dissassemble the BladeSystem down to every last piece. There are picture based instructions that come with the BladeSystem which make this very easy to do. Once it’s completely in pieces, then you can rack the empty cage fairly easily with the help of one other person. Then once it’s secured in the rack you can start to put it back together again. This is a lot easier than carrying it fully populated and your back will thank you for this. 🙂

For #2, go to HP’s website and follow the instructions regarding the mezannine mappings for the C7000 or C3000 (depending on what you’re using) BladeSystem. Then you can end up putting the interconnects in the right bays and your BladeSystem won’t give you a bunch of errors on boot up!

-Cheers, RP

May 25, 2009  12:27 AM

Offsite Backups in Large Data environments without tape

Raj Perumal Raj Perumal Profile: Raj Perumal

Hi folks, I wanted to talk backup for a second. Now in large data center environments backup strategies aren’t always cut and dry. You are usually dealing with large amounts of data and very small backup windows.

We’re talking about servers that need to be up 24/7 and 365 days a year and lots of data going through them on a daily basis. Once you get into counting your backup size by terabytes vs gigabytes it’s time to start looking at some different strategies.

VTL has always been a good idea, offloading to disk and then offloading to tape later when you have more time to do it. This way you can offload your backups at high speed in your short window. However an often overlooked method which has started to gain serious traction is deduplication. Many vendors offer it and some even combine it into their VTL offerings. Deduplication can achieve an average compression ratio of 20:1 and at it’s best go as high as 50:1 and even higher sometimes.

So take a moment to look at the deduplication offerings out there. Some of them even offer the ability to replicate the deduped data to an offsite location over the WAN without using tape at all. This way you can save on the cost of tape.


May 23, 2009  3:05 AM

Containing Rogue Wireless Lans in your Corporate Environment

Raj Perumal Raj Perumal Profile: Raj Perumal

So one of the more common technologies I see being implemented in my day to day work is wireless. Wireless is one of those mixed bags. It’s a great technology that offers a lot of convenience to your users but at the same time it can be a huge security risk and a pain to maintain.

One of the more common problems you might seen in a corporate environment is users buying their own cheap wireless access point like a Linksys or D-Link from their local electronics retailer and plugging it into a network port in their office to give them wireless capabilities. This isn’t only bad for security, but it can also interfere with any wireless networks you already have setup.

Luckily Cisco has an answer to this problem. If you use the Cisco wireless controllers, they have a feature built-in to stop this. They refer to non-authorized wireless in your environment as “Rogue AP’s”. These rogue AP’s can be “contained” by use of the Cisco software. All you have to do is tell the wireless controller to contain any rogue AP’s it sees and from that point on it renders those AP’s useless in your corporate environment.

For information on the Cisco wireless solution, check out this link here.


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