VMware Consultancy Services

Scenario When we use thin provisioned vmdk, the size of the vmdk expands as we pile up data in the OS. But if we delete some data from OS, the reclaimed space in the OS will not be reclaimed from the vmdk. It will continue to occupy the maximum space it have ever used after creation. Resolution There is no resolution to reduce the size using vSphere client. For this you may need to seek the help of putty or cli. - Login to the ESXi using putty - Browse to the vmdk location (eg: cd vmfs/volumes/datastore1/VMname - List the available vmdk files in this location using the command: ls –lh *.vmdk - To know the actual size occupied by the vmdk file <   du –h *.vmdk - To shrink the size of the vmdk file vmkfstools -K AD01.vmdk - Re check the actual size of vmdk now. 

Sometimes a VM is stuck and can’t be shutdown/rebooted with vSphere Client. On ESX, you could login and use command kill –9 to kill the VM. Same can be done from PowerCLI also. This functionality has been added to PowerCLI in version 4.1 Update 1. Open PowerCLI and connect directly to the Esxi host. # Connect-VIServer -Server -Credential $(Get-Credential -Credential root) It will ask you for the root password. Fetch the ESXCLI object with the Get-ESXCLI cmdlet. $esxcli = Get-EsxCli -Server Run the following method of $esxcli to list all the running VMs and their World ID. $esxcli.vms.vm.list() | Format-Table -Property DisplayName, WorldID Search the WorldID of the VM you want to kill and run the following command to kill the VM. $esxcli.vms.vm.kill(“soft”, ) If the above command reports back with true it means the VM was killed successfully. If you get false , try replacing soft by hard and finally by force . Use force only as a ...

Steps for cloning VM using SSH: ·          SSH to the ESXi host ·          Identify the path of the source (say, /vmfs/volumes/datastore1/SourceVM/ where sourceVM is the name of the source VM) ·          Create a new folder in the desired datastore mkdir /vmfs/volumes/datastore1/DesintationVM where DestinationVM is the name of the new VM ·          Clone the sourceVM vmdk to the newly created folder DestinationVM vmkfstools -i /vmfs/volumes/datastore1/SourceVM/sourceVM.vmdk /vmfs/volumes/datastore1/DesintationVM/DesintationVM.vmdk ·          Once cloning is completed, proceed with the creation of the new VM using vSphere client. ·          In the option where you need to provision the harddisk for the new VM, choose 'Use an e...

Symptom: The host and VMs in a vcenter server appears to be disconnected. Issue: The host and its corresponding vms could appear as disconnected due to issue with any of the following services. vpxa - a service which runs in the esxi host. This service communicates with vcenter server. hostd - core service which runs in the esxi host vpxd - a service which runs in the vcenter server which communicates with the vpxa Resolution: 1. Try to ping the ESXi host. This ensures that the host is reachable 2. Ensure you can login to the VMs remotely. This ensures that VMs in the host are working fine. 3. Try to login to the ESXi host using vsphere client. This ensures that the hostd services are running perfectly. If this step fails, restart the hostd service using putty. 4. If the above three steps worked fine for you, the issue would be with the vpxa or vpxd service. In that case, first try to restart the vpxa service in the host and if that didnot resol...

Problem: Unable to convert a VM with Paravirtual SCSI Disk using VMware Converter 4.3 When we to convert a VM with Paravirtual SCSI Controller, VMware Converter 4.3 throws an error and the task fails with Status: FAILED: An error occurred during the conversion: When you start analyzing the log files you will get an error “Unknown controller” is detected. Reason: VMware Converter 4.3 doesn’t know the Paravirtual Controller! Resolution: Perform the following steps to resolve this issue Power off the VM Change all Paravirtual controllers to LSI Logic Perform the Conversion on powered off VM and make sure VM is not powered on automatically after convert. Change SCSI controller back to Paravirtual Power on VM How to Change SCSI Controller Select the VM and click on Edit Settings . Select the SCSI Controller from devices list and click on change type button. Note: This is a known bug in VMware Converter 4.3 as reference on www.vmware.com

CPU TROUBLESHOOTING If ready time <= 5%, there’s no problem. If ready time is 5% <=> 10%, there might be an issue. If ready time is => 10% there’s a performance issue. Check if the virtual machine’s CPU is not limited. Check if there’s CPU over commitment all the time, occasional spikes are no problem. If it’s an SMP virtual machine check if the application is multithreading and actually using the resources. If the ESX host is saturated reduce the number of virtual machines. MEMORYTROUBLESHOOTING Be careful with setting virtual machine memory reservations. When memory is touched by the VM, the other virtual machines can’t use the memory anymore. Only configure what the virtual machine really needs. Don’t set memory limits, set an appropriate virtual machine memory size instead. Do not disable page sharing or the balloon driver. Ballooning is OK as long as the guest OS isn’t using it’s own page file for active memory swapping. The use of large pages results ...