Vsphere, ESXi, and vCenter differences

This is a direct re-post from an article I read on mustbegeek.com, but it was a much needed reference in the event I had a brain fart and forgot these important differences between the VMware suites.

 Difference between vSphere, ESXi and vCenter

VMware Inc. is a software company that develops many suite of software products specially for providing various virtualization solutions. There are many cloud products, datacenter products,  desktop products and so on.

vSphere is a software suite that comes under data center product. vSphere is like Microsoft Office suite which has many software like MS Office, MS Excel, MS Access and so on. Like Microsoft Office, vSphere is also a software suite that has many software components like vCenter, ESXi, vSphere client and so on. So, the combination of all these software components is vSphere. vSphere is not a particular software that you can install and use, “it is just a package name which has other sub components”.

ESXi, vSphere client and vCenter are components of vSphere. ESXi server is the most important part of vSphere. ESXi is the virtualization server. It is type 1 hypervisor. All the virtual machines or Guest OS are installed on ESXi server. To install, manage and access those virtual servers which sit above of ESXi server, you will need other part of vSphere suit called vSphere client or vCenter. Now, vSphere client allows administrators to connect to ESXi servers and access or manage virtual machines. vSphere client is installed on the client machine (e.g. Administrator’s laptop). The vSphere client is used from client machine to connect to ESXi server and do management tasks. So now what is vCenter? Why we need it? Try cloning existing virtual machine using just a vSphere client without vCenter server.

vCenter server is similar to vSphere client but it’s a server with more power. vCenter server is installed on Windows Server or Linux Server. VMware vCenter server is a centralized management application that lets you manage virtual machines and ESXi hosts centrally. vSphere client is used to access vCenter Server and ultimately manage ESXi servers. vCenter server is compulsory for enterprises to have enterprise features like vMotion, VMware High Availability, VMware Update Manager and VMware Distributed Resource Scheduler (DRS). For example, you can easily clone existing virtual machine in vCenter server. So vCenter is another important part of vSphere package. You have to buy vCenter license separately.

The diagram above shows vSphere suite in a more descriptive way. vSphere is a product suite, ESXi is a hypervisor installed on a physical machine. vSphere Client is installed on laptop or desktop PC and is used to access ESXi Server to install and manage virtual machines on ESXi server. vCenter server is installed as virtual machine on top of ESXi server. vCenter server is a vSphere component which is mostly used in large environment where there are many ESXi server and dozens of virtual machines. The vCenter server is also accessed by vSphere client for management purpose. So, vSphere client is used to access ESXi server directly in small environment. In larger environment, vSphere client is used again to access vCenter server which ultimately manages ESXi server.

Reference

http://www.mustbegeek.com/difference-between-vsphere-esxi-and-vcenter/

What happened to my VM networks(VLans)?

Okay...so I'm building a mass amount of VMs using Vmware ESXi 5.1 to construct a Windows domain with rogue systems to practice my uber hacking skills:) and something goes terribly wrong. I can no longer add my VMs to the VM networks that I created that are linked to VLANs on my Cisco switch. I did some reading and there is a setting on the Vswitch properties that can increase/decrease the amount of virtual ports per virtual switch. I had it set to only 120 ports...I have 500+ VMs. Okay, so I set the threshold to the max of 4088 to both of my virtual switches. Voila! My virtual switches disappeared. My VM networks all gone.

Based on this article, the issue occurred when the total number of ports exceeds 4608. It doesn't matter if you have one or several virtual switches configured. The number of total virtual ports cannot exceen 4608. B-I-N-G-O-!

I made the changes for each virtual switch(2) that I am using to have 504 ports each and rebooted the ESXi server. 

All is well in virtualization land. :)

Simple Exchange 2010 installation

Cut the bull crap. I have been through what seems like endless amounts of tutorials, blogs, and other instructional guides on a simple Exchange 2010 install for a small Windows domain environment(100 total systems/200 AD users). Why so many nonsensical/fluff included in these guides is beyond me.

Here is what worked for me:

• Pre-reqs: 
• Configure a Windows 2008 r2 domain controller and DNS server. (same system is fine)
• Create a domain account that is part of the following groups: <Schema Admins, Domain admins, and Enterprise Admins>
• Load the Exchange 2010 DVD and perform the three separate commands from command line on the DC itself since it also 'extends the AD schema'. Make sure you prepare AD first: 
• Log in as a member of the schema admins domain security group. If there is an existing Exchange organization in place, run setup /prepareAD from the drive containing the Exchange 2010 installation DVD. If there is no existing Exchange organization in this environment, run setup /prepareAD /OrganizationName:”<the name of your new exchange organization>”. In the example below, the following command is used: setup /prepareAD /OrganizationName:”First Organization”.
  
• Schema Updates (setup.com /pl, /ps and /p)
• Build a separate Windows 2008 r2 server with all updates for you Exchange server
• Load the Exchange 2010 DVD
• From command line: Install the Exchange pre-reqs:
• Run from this directory of the DVD: install\scripts>ServerManagerCMD -ip Exchange-Typical.xml
• Reboot
• Run the setup.exe file from Exchange DVD and complete installation.

• Make sure you uncheck those two options in IE as was previously mentioned in an earlier post or you will not be able to open the Exchange MMC.
• Then click on Exchange MMC and allow it to complete its initial setup.
• Bingo bango! Finished.

*Now remember this is for a small business or lab environment. When you get into Exchange clusters Edge Transport servers yada yada yada, it will be more complex than this. If your objective is to have an Exchange mail server to work for your internal network, this is all you have to do.

Exchange 2010 mmc 'snap in not responding'

Turn off (Uncheck) “Check for publisher’s certificate revocation” & “Check for server certificate revocation” options on the server/workstations you are starting the EMC (Exchange Management Console) on

·        In Windows Internet Explorer –> Tools –> Internet Options –> Advanced tab
·        In the Security section, uncheck the below two options “Check for publisher’s certificate revocation” & “Check for server certificate revocation”

How does this relate to the EMC in Exchange 2010  ? well Exchange tries to connect to the certificate revocation list (CRL) Web site. Exchange examines the CRL list to verify the code signing certificate.

I have also noticed that unchecking the two options above speed up the start time of EMS (Exchange Management Shell)


Taken from: http://blogs.technet.com/b/nawar/archive/2011/06/03/exchange-2010-management-console-emc-is-very-slow.aspx