When new end user VMs are provisioned in Horizon VDI and these VMs use Instant Clones and/or App Volumes, the end user VMs get assigned the same UUID for a brief period (duplicate UUID), as a result cache operational state of ‘Write-Back’ is not applied to these VMs, only ‘Write-Through’…
All ESXi versions
All the below configurations needs to be applied to VirtuCache and your backup software for VM backup times to improve. 1. Apply the ‘Backup-VM’ caching policy to your Backup proxy VMs. 2. The VM that is being backed up needs to be cached by VirtuCache either using the Write-Through or…
VMware VMs have two UUIDs – BIOS UUID and instance UUID. VirtuCache doesn’t support Write-Back policy where multiple VMs in the same vCenter share the same BIOS UUID, even if these VMs have different Instance UUIDs. When using the cloning feature in Datrium (now end of lifed), the cloned VM…
Because VirtuCache uses different APIs for ESXi 6.x and 7.x, VirtuCache cannot establish peer connections between hosts that are on ESXi 6.x and 7.x, as a result, VirtuCache cannot replicate (mirror) the write cache between hosts that are on ESXi 6.x and 7.x, and so VirtuCache’s ‘Write-Back 1 Replica’ policy…
A prerequisite to installing VirtuCache is that all other host side caching software be uninstalled. Infinio is one such host side caching software, recently end-of-lifed. Below are steps to ensure that Infinio is indeed removed from the ESXi host. SSH to the ESXi host and make sure the below command doesn’t…
The PowerCLI script below changes PSP of all LUNs attached to all hosts in a vCenter to the VirtuCache Round Robin PSP (VNX_PSP_RR) and sets IOPS=1 for this PSP. This script needs to be run only after you have VirtuCache installed on all hosts in that vCenter. $vcenter = “–enter-vcenter-ip-or-dns-here–”…
In rare cases, one or more VMDKs on a VM could have its ‘sharing’ field (drop-down field in ‘Edit Settings’ at the VM level) set to multi-writer, in which case it is not possible to move that VM to Write-Back caching mode. Such VMs can only be set to ‘Write-Through’…
If some VMs are not in Write-Back operational state when caching policy is set as ‘Write-Back 1 Replica’, it could be because of VirtuCache is not claiming the LUN when it was installed. You can verify this symptom by issuing ‘list-vms’ command in vnxcli (type vnxcli in ESXi CLI) for…
VirtuCache plugin for vCenter Flash client doesn’t show correct performance data (latencies and throughput) when the VM is a Horizon or XenDesktop VDI VM (using Linked Clone), Xenapp VM (that uses a Linked Clone base disk) or a VM that has a snapshot, in ESXi 6.0 and 6.5. This is…
VirtuCache performs disk heartbeats periodically. If there are Datastore connectivity issues in VMware, these disk heartbeats may fail intermittently, in which case VirtuCache treats the Datastore as unreachable and VMs that are in the Datastore don’t show in the VirtuCache GUI. VirtuCache takes this precautionary measure to prevent the Administrator from changing…