ESX

How to monitor free space on a LUN?

Hi folks! So further to my last post, once you’ve decided on free space for your LUN, how the heck do you monitor it?

There are a few scripts out there that will do this for you and a few free programs that will show you the free space. But how do you get it to check and then email you an alert if you go past your set threshold? Veeam of course!

The good people at Veeam have a product called Veeam Monitor, which will not only monitor your storage but also monitor a myriad of other VMware related things. Features such as hardware monitoring and performance analysis will also help you with your VMware administration duties.

You can check out the free version of Veeam Monitor here and if you like it you can then opt to purchase the full product.

-RP

How much free space is needed on a LUN for VMware?

Hi folks! One of the common questions you might find in the virtual world with VMware is how much free space do I leave on a LUN? When is it not enough?

A common mistake is to think you only need enough free space for the size of the VM itself and not much more. Well if you do that you’ll quickly find out the hard way that you should have allocated more. You see VMware needs space for things such as snapshots and space for emergency situations where you might need the space for shuffling things around from LUN to LUN.

The general consensus for free space on a VMware LUN is 10% to 20% free space. This isn’t just for snapshots, but also to account for any emergencies you might have to deal with on a VM where you need the free space. So if you don’t have  10% to 20% free space, then essentially you should treat the disk as full for all intents and purposes. 20% can be considered on the conservative side but it doesn’t hurt to be cautious.

I have heard people say 10% to 15% is good enough but only if you have very strict snapshot policies to ensure that you are monitoring the disk space closely.

-RP

Another way to P2V NT

Hello again folks! This is an update to a previous blog post. So I was P2V’ing another Windows NT server the other day and I was able to get P2V to work with an older version of VMware converter.

VMware converter version 3.0.3 is the version I used and it installed into Windows NT just fine (reboot required). Then I was able to launch the application and connect to my ESXi server and launch the conversion of the physical machine.

This means I was able to do a hot clone of Windows NT 4. I hate working with NT boxes but at least we have an easy method to virtualize them. A lot of NT servers out there are on ailing hardware that is not on warranty so having a method to hot clone them is always a good thing!

-RP

Faulty ESX USB keys from HP

Hi guys, I wanted to chat about something I’ve run into in my experiences. Faulty USB keys for ESX! As you know, VMware has the ability to load onto a server using a USB key instead of hard drives. Well I have now seen an issue with this, not with VMware so much as with HP branded ESX USB keys.

If you bought ESX USB keys from HP along with your servers you might have a faulty set of keys. Apparently the keys start to fail and the servers either freeze or cause weird errors like the VMware purple screen of death. I personally ran into this on over 40 HP blades using HP USB keys.

Luckily the good folks at HP have acknowledge this and have posted a fix for this. HP will send you a replacement USB key if you find that you have an issue. They also have posted what to look for on the USB key to determine in advance whether you have one of these faulty keys.

You can check out the following links for more information:

• (USB Key w. ESXi e - bad experiences)

• Warning — faulty HP ESXi USB Keys!

• (HP Knowledge Base article)

-RP

P2V’ing old Windows NT servers with less than 264 MB of RAM

So you’ve been tasked with consolidating a bunch of old servers. You break out the old VMware converter cold clone cd and you start going to town. But then you come across an old Windows NT server with less than 264 MB of RAM. You put the CD in the drive and you boot to CD, you wait for a painstakingly long time and eventually an error spits out on the screen. You don’t have enough RAM to run the CD!

The VMware cold clone cd requires at least 264 MB of RAM to run. Now in this day and age with most servers this is not really an issue. However with old Windows NT boxes this poses a big problem. There’s also no Windows NT install for converter. What do you do?

Well if you still have an old VMware P2V Assistance CD and license kicking around you could use that. Of course if you don’t have that, what are your options? Well, if you can’t create a new virtual server and transfer the services from the old server to the new server you’re probably stuck with disk cloning like Ghost.

Ghost isn’t a trouble free process but it should get the job done with a bit of tweaking.

-RP

vSphere Announced!

Hi folks, so the vSphere annoucement is now out and we have a ton of cool new features to look forward to! The announcement was all the buzz on Tuesday!

The virtual machines themselves seem beefed up with access to more RAM and CPU, and VMware is capable of more IOPS now as well. Backup is made easy with vSphere, as well as more security features introduced into the product. A more refined networking strategy was also introduced with the concept of Cisco’s virtual switch embedded in vSphere.

The editions available now are:

• Essentials
• Essentials Plus
• Standard
• Advanced
• Enterprise
• Enterprise Plus

VMware has given the customer a lot more choice and flexibility with these options and every size business should be easily able to find the right product to fit their needs.

If you own a current version of VMware with support, you will be eligible for the upgrade the moment it is released. Even though the announcement was on Tuesday, the actual software will only be available within little less than a month. I’m assuming after that happens we will see a rush for individuals to download and get quickly upgraded. Just remember to leave some older VMware servers lying around in case your upgrades don’t go as smooth as you’d like so you have somewhere to roll back. This is just part of good patching practice!

-Cheers, RP

vSphere coming soon to a theatre near you!

Hi folks, looks like we have an announcement on the horizon! VMware has announced that they are going to be making a major announcement for vSphere on April 21st, 2009!

For those of you that don’t know, vSphere is the next version of VMware ESX (ESX 4.0). They have renamed it vSphere and it’s coming out soon. This does not bode well for Microsoft and Citrix as they will now have to play catch up again with all of VMware’s new features!

Some of the features they are announcing? vStorage and vSwitches for starters! Things are really going to start to heat up once vSphere comes out and it will be interesting to see how the competition responds. Like I always say, this competition is going to be great for the consumer!

-RP

Citrix XenServer now free

Hi folks, you may have heard that Citrix XenServer is now free. This is great news for the virtualization world because now we have yet another fully capable virtualization product without virtual machine limits (the old Xen Express had a 4 machine limit) to to compete with Microsoft and VMware.

However I do have to speak to something regarding this recent announcement. Apparently some people have been saying that this is the first free hypervisor that is actually capable of being deployed in a production environment. Now I don’t know about you but that smells like a lot of marketing BS to me.

As far as I’m concerned even VMware’s free ESXi has always been a fully capable production environment product. I have used it in countless customer sites and it runs solid, stable and with great performance. Likely that comment is designed to affect the opinions of people who haven’t had much experience with virtualization and aren’t in the know from trying it themselves.

Citrix is joining forces with Micrsoft with the Citrix Essentials product which support Hyper-V and XenServer. I think this is going to backfire because Microsoft is not going to let Citrix’s virtualization product eclipse their own. Sure they have had a great relationship for years and years, but when it comes to this virtualization war, Microsoft is not going to settle for being behind Citrix.

On the other side, VMware will have to watch out, because it’s obvious it’s competitors have VMware set firmly in their sights as their number one target.

-RP

Enabling SSH on a VMware ESXi Server

For those of you that are used to having service console access in VMware ESX server, you might find yourself in for a bit of surprise when you try and do this with ESXi. By default you do not have access. However there is a way to enable access to the console.

Why do you need access to the console? With access to the console this gives you the ability to troubleshoot larger support issues when things aren’t working the way they should and it also enables you to run some pretty cool scripts that are available out there on the Internet.

The ESXi console uses BusyBox so it is different from ESX even after you get console access. To enable SSH access to the shell, please do the following:

• From the ESXi console hit Alt-F1
• Type in the word unsupported and hit enter (you will not see the characters appear on the screen)
• Type in your root password
• Edit the /etc/inetd.conf file by typing in vi /etc/inetd.conf
• Scroll through the file until you find the line that says #ssh and delete the # sign
• Save the file
• Now you can reboot the ESXi server and you will have shell access
• Alternatively you can run the /sbin/services.sh restart command to restart the management services without rebooting the box.

-RP

VMware snapshots, live it, love it, learn it!

Hi folks, here’s a standard feature of VMware that a lot of people take for granted that I thought would bear mentioning. Snapshots!

So you have an application or patch you want to install and you don’t know what effect it will have on your server. What do you do? Take a snapshot! With VMware you have the ability to take a snapshot of your OS at that point in time and then make whatever changes you desire. After your changes are made you can check to see if everything is working. If there are issues you can just select the snapshot and revert back to where you were before.

I find it quite surprising how many people actually have VMware and forget to use this feature as if they’ve forgotten it’s even existed! Snapshotting can be your best friend when doing upgrades, don’t forget it!

-RP