vSAN host cannot be moved to the destination cluster: vSAN cluster UUID mismatch

This is a very quick post regarding the error message received below when attempting to add a VMware ESXi host with an existing vSAN partition to a new vCenter. The vSAN host cannot be moved to the destination cluster: vSAN cluster UUID mismatch In my case the complete error is as follows – Add hostStatus: … Read more

HPE CLX Virtual Machine Protection Fails

Recently a colleague was attempting to configure the cluster extension protection (CLX) which is required by our Active/Active HPE 3PAR storage setup. Our Microsoft Failover Clusters are stretched over geographically separate sites and the Cluster Share Volumes (CSV) are spread over the 3PAR storage arrays in each site. We use the CLX software to manage … Read more

Unexpected Large Page File Troubleshooting

This week one of my colleagues has been performing updates on our hypervisor hosts including those running Hyper-V. During this work we received alerts from our monitoring system to indicate two of the hosts had essentially run out of disk space, obviously a little worrying. We stopped the update process while troubleshooting was carried out … Read more

HPE 3PAR Remote Copy Volumes Both Read Only

I recently ‘enjoyed’ working on an issue where a 3PAR remote copy group issue resulted in both virtual volumes entering a read-only state. I’ve seen a similar problem where both copies go into a read-write state which is probably more worrying when it happens. Let’s take a look at the problem, the data I had … Read more

Get Windows NTFS Block Size

Windows systems write blocks of data to underlying storage – the size of these blocks is given various terms, for example – Block size Allocation unit Cluster size The important thing to consider is that this unit of allocation can have an impact on the performance of systems. By default Windows will format a disk … Read more

Set Cluster Log Size and Verbosity in Microsoft Server 2008 R2

Recently a critical cluster system had a bit of a hiccup wherein the SQL resource failed between nodes a few times and then gave up. Most of my clusters run on Microsoft Server 2012 R2 so I tend to use PowerShell for everything, in this case the cluster is an older one running Server 2008 … Read more

Disable Automatic Chkdsk on Windows Failover Cluster

These days it is pretty rare to be prompted to run a chkdsk on a Microsoft system, I certainly remember it being a more frequent occurrence on older hardware and OS versions. That being said, there are still occasions where Windows will prompt for a chkdsk and this post deals with a particular event – … Read more

Microsoft Failover Cluster–Unable to remove a CSV due to dependency

We have a Microsoft 2012 R2 Failover Cluster (FOC) with disk resources presented from our HP 3PAR SAN. At some point two of the volumes were removed on the 3PAR however they had not been removed as Cluster Shared Volumes (CSV) on the FOC. When we attempted to remove the disks as CSV resources and … Read more