Emulated version of the AMD 79C970 PCnet32. Older 10 Mbps NIC with drivers available in most 32-bit guest OSes except Windows Vista and newer.
Paravirtualized adapter, optimized for performance in virtual machines. VMware Tools is required for VMXNET driver.
Emulated version of the Intel 82545EM 1Gbps NIC. Available in Linux versions 2.4.19 and later, Windows XP Professional x64 Edition and later, and Windows Server 2003 (32-bit) and later. No jumbo frames support prior to ESX/ESXi 4.1.
Emulated version of the Intel 82574 1Gbps NIC. Only available on hardware version 8 or newer VMs in vSphere 5.x. Default vNIC for Windows 8 and newer Windows guest OSes. Not available for Linux OSes from the UI.
Paravirtualized adapter, providing more features than VMXNET, such as hardware offloads and jumbo frames. Limited guest OS support for VMs on ESX/ESXi 3.5 and later.
Paravirtualized adapter, unrelated to previous VMXNET adapters. Offers all VMXNET2 features as well as multiqueue support, MSI/MSI-X interrupt delivery, and IPv6 offloads. Supported only for hardware version 7 or later with limited guest OS support.
The vmxnet adapters are paravirtualized device drivers for virtual networking. A paravirtualized driver improves performance since it shares a ring buffer between the virtual machine and the VMkernel. This uses zero-copy, reducing internal copy operations between buffers, which saves CPU cycles. The vmxnet adapters can offload TCP checksum calculations and TCP segmentation to the network hardware instead of using the virtual machine monitor’s CPU resources.
vSphere administrators should know the components of virtual machines. There are multiple VMware file types that are associated with and make up a virtual machine. These files are located in the VM’s directory on a datastore. The following table will provide a quick reference and short description of a virtual machine’s files.
A very nice tool that an administrator can download is a virtual appliance called the vMA which is Linux based (SUSE Linux Enterprise Server 11, SP1), it has several components, including the vCLI and vSphere SDK for Perl. The requirements for the vMA aren’t too crazy, must have 1 vCPU, at least 600 MB of memory, 3GB disk minimum and needs to be deployed on one of these platforms:
– vSphere ESX 4.0 U2 or newer
– vSphere ESXi 4.1 or newer
– vCenter 4.0 U2 or newer
This appliance gets deployed like any other; first we download it from VMware’s website. Once we have the *.ova or *.ovf file then go to File > Deploy OVF Template in the vSphere Client and finish the wizard.
The vMA will allow us to manage our hosts via command line as well as run scripts. Our vMA commands sent directly to our host are send via vSphere SDK for Perl API, and if we are sending commands to a host but through vCenter then it will be sent to vCenter via vSphere SDK for Perl and then from vCenter to the host using vCenter’s private protocol.
Using our vifp interface, we can add, show, or remove target servers. A target server is what we are trying to connect to here. If we want to go ahead and set that target as the default for this session then we will type to vifptarget command. We can choose to establish multiples servers as target servers. We will just need to use the – -server option to go ahead and specify which one we are going to be running our commands against. So, for example:
To add a server as a target:
To list target servers:
To set a server as the target for the vMA session:
To remove a target server:
vCenter Server provides storage filters in its advanced settings to help you avoid storage device corruption or performance degradation that can be caused by an unsupported use of LUNs. These filters are available by default. We have a few different ones to choose from: VMFS filter, RDM filter, Same Host and Transports filter, and Host Rescan Filter.
We see the keys on the right next to the different kind of filters, we can look for these in vCenter Advanced settings to change or disable them. To do this:
– Log into vCenter using the vSphere Client
– Go to Home > vCenter Server Settings
– Click Advanced Settings
– Enter or modify the keys above
– Click ok