unhide recovery partition
ESX 3.5

Unload unnecessary modules from your ESX host.

“Turn off what you do not need” is my motto 🙂 . So, if you are not using the VMFS-2 (which you probably aren’t using since ESX 3.x) and/or NFSClient in you environment than you can safely unload these modules from your ESX host. You can list currently loaded modules with #esxcfg-module –q and if you want to disable the modules mentioned above then: Login to you ESX host as root user First, unload the […]

unhide recovery partition
ESX 3.5

Monitor VMkernel activity with the tail command.

The tail command displays last 10 lines of a file and with the –f (follow) parameter you can see the data appended to it. So, if you want to see what is going on in the vmkernel of your ESX host: Login to you ESX host Type: #tail –f /var/log/vmkernel Watch for new events to appear If you want to terminate the process,  press CTRL + C Nice & simple 🙂 Cheers! – Marek.Z

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ESX 4

Configure Jumbo Frames on Hardware iSCSI HBA in ESX 4.

Before you begin, check the names of the vmhba adapters on your ESX server. From the vSphere Client go to Configuration tab and click on Storage Adapters. Now, to set Jumbo Frame support (MTU 9000) on your hardware iSCSI HBA, follow these steps: Login as Root user on your ESX server. Type: #esxcfg-hwiscsi –j enable <vmhba#> If successful, you should get the “MTU size successfully set to : 9000” message. To verify the change type: #esxcfg-hwiscsi –l  <vmhba#> All done! Cheers! […]

unhide recovery partition
ESX 3.5

Kill an unresponsive VM on an ESX server.

If you want to kill an unresponsive VM on an ESX server and it cannot be turned off with the vmware-cmd stop hard command then try the following: Logon the ESX server as Root and type: #vm-support –x to find the VMID of the unresponsive VM. Next, type: #vm-support –X <VMID> to kill the VM. Answer the questions as desired and wait until the ESX server finishes the job. Cheers! – Marek.Z

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ESX 4

Configure software iSCSI networking from the CLI.

Follow these steps to configure software iSCSI networking on an ESX server. In this case I’ll be creating a new vSwitch, new Port Group on the new vSwitch and I’ll add the VMkernel port to the vSwitch. This setup will support the Jumbo Frames (MTU 9000). After that I’ll add an iSCSI target to the iSCSI software adapter and rescan the adapter for new targets. Login as Root user on your ESX server. List the vSwitches with #esxcfg-vswitch -l and check the next available […]

unhide recovery partition
ESX 3.5

Start/stop a VM from the CLI.

Follow these steps to start or stop a VM from the CLI of your ESX server: First, find the full path to your virtual machine by typing: #vmware-cmd -l To start a VM type: #vmware-cmd <path to your VM> start To stop a VM type: #vmware-cmd <path to your VM> stop (hard). This option is optional. It will force a hard stop of your VM. Cheers! – Marek.Z

unhide recovery partition
ESX 3.5

Grant the Root user SSH access.

Granting SSH access to the Root user is not recommended from the security point of view. But, when you are in a secured environment you can safely enable the SSH access for the Root user. Login on your physical server as Root user. Type: #vi /etc/ssh/sshd_config Find the PermitRootLogin value in the file and change it from “no“ to “yes“. Save the file. Restart the sshd service by typing: #service sshd restart You can now […]