ESX and ESXi

Today while creating new VMs from a template I got the error “the server fault invalidargument had no message” when editing the VM settings, the settings were modified successfully but the error was present whether a change had been made or not to the settings of the VM. A quick search of the web suggested removing said VM from the inventory and re-adding from the datastore, for many this fixed the issue but not for me.

I ran into this issue yesterday while reconnecting hosts in our vCenter Server following a complete reinstall - the reasons for which are a long story, but suffice to say that there were new certificates and the host passwords were encrypted with the old ones. The LUNs had been unpresented at the hardware level by the storage team, but had not been unmounted or removed from vCenter. This is not the way to remove storage - let me re-iterate: remove storage properly.

Here’s a lesson in checking the basics! I added new ESXi 5 host to a cluster today and spent a good couple of hours troubleshooting the error: vSphere HA agent for host [Host’s Name] has an error in [Cluster’s Name] in [Datacenter’s Name]: vSphere HA agent cannot be correctly installed or configured After a few basic checks, migrating the host in and out of the cluster and rebooting, I headed off to google and began troubleshooting.

If you are close to the VMware ESXi storage path limit of 1024 paths per host, you may want to consider the following: local storage, including CD-ROMs, are counted in your total paths. Simply because of the size and age of the environment, some of our production clusters have now reached the limit (including local paths) - you see this message in the logs [2012-08-20 01:48:52.256 77C3DB90 info ‘ha-eventmgr’] Event 2003 : The maximum number of supported paths of 1024 has been reached.

I’m currently updating a very small 4-host cluster built for a specific application within our datacentre, the hosts are IBM HS22 blades. Since we have the VMware Update Manager infrastructure in place already, I downloaded the IBM ESXi 5.0 Update 2 ISO and imported it into Update Manager, created a baseline and then applied it to the cluster. I scanned the cluster with the baseline and was issued this warning for each host:

Recently I installed and configured a client’s new ESXi host, they’re a small company and only require a single host. The host in question was an IBM x3650 M3, an excellent workhorse for virtualisation and one of 5 or 6 of the same model that I’ve installed in the last year. In addition to the onboard Broadcom Dual Gigabit NIC, we always install at least a second Intel PCIx Dual Gigabit card for resilience/redundancy/performance.

Recently I had cause to configure iSCSI multipathing on a test ESXi server. The production environment servers use iSCSI HBAs to connect to the back end storage, so multipathing them is a straight-forward setup. It’s good practice to separate VMotion, virtual machine and iSCSI traffic, it also helps you manage those logical and physical connections. Connect to your ESXi server using the vSphere Client and select the host. Go to the configuration tab and click “Add Networking…”.

vMA is available as a Virtual Appliance (OVF) from VMware. To install it on VMware Workstation 7, open Workstation and select Import or Export to import a new OVF, the URL for the latest OVF for vMA is on the vMA download page As per this article on virtualkenneth.com, you need to edit the VMX file to change the SCSI card and OS type, otherwise you’ll have a kernel panic on boot.

Configuring the Virtual Environment and Virtual Machines Note – this configuration will work for ESXi 4 upwards due to the server 2008 MSCS requirement for persistent SCSI-3 reservations. The first step is to create a new vSwitch for the host-only cluster heartbeat network, don’t assign any network adaptors to the switch as it’s going to be local only. Create a new virtual machine with a single hard disk. For the purposes of this test, I’ve assigned 2 vProcessors, 1GB RAM, 30GB drive for the OS, 1 vNIC in the default vSwitch0.

A.K.A Why not to use snapshots I ran into a slightly confusing problem today - our SQL servers are all created with 4 disks on 4 separate LUNs (System, Swap, SQL Data and SQL Logs). When viewing the server through Virtual Center I couldn’t see all of the LUNs, just the System LUN. It’s not a major problem as the VM can see the storage, but a little annoying when you have to remember what LUN the disks are on.