If VirtuCache driver build numbers on hosts in the same ESXi cluster are different, then VirtuCache doesn’t create peer connections between hosts with mismatched build numbers, and hence any VirtuCache tasks that require such a connection over the replication network, don’t happen. So read directs in case of write-through caching…
All ESXi versions
If a SSD starts to fail, it first starts to slow down , especially for writes, then it becomes read only , and at that point VirtuCache is not able to write to the SSD so VMs and Datastores move to uncached mode automatically. Your VMs go back to performing as…
If the write-replication network fails, then VirtuCache keeps trying to replicate writes for 30seconds, during which time writes are not being acknowledged. After the 30 second period, VirtuCache times out the writes. Then VirtuCache freezes IO till the write cache is synced with backend SAN. Since we keep upto 2…
If you are not able to attach an SSD to VirtuCache, and if there are no other obvious issues listed here that prevent the SSD from being assigned to VirtuCache, then its most likely that there is not enough memory available to accomplish this task. VirtuCache runs into this out-of-memory condition…
‘Write-Back One Replica’ Caching Policy ensures that a single host failure in a cluster doesn’t result in data loss. Now if you have a 2-host cluster and one host fails, then the VMs that are in ‘Write Back’ operational state on the host that is still up and running will…
If after installing your permanent license key vib, the VirtuCache GUI shows no data, then please unload and reload the driver [http://virtunetsystems.com/knowledgebase/loading-and-unloading-virtucache-driver/].
Caching policy of ‘Write-Back 1 Replica’ is assigned to VMs or Datastores, but the operational state remains ‘Write-Through’. The reasons could be one or more listed below. The VirtuCache replication network is the vmotion network and the vmotion network might be using the vmotion stack that precludes all other traffic from…
This article applies to snapshots in VMware (not for storage appliance snapshots) that are used for various purposes including for backups by Veeam, Commvault and other backup software. VirtuCache triggers accelerated destaging when a snapshot is created and ensures that the base snapshot is not readable by other hosts until…
If you create a new VM, or restore a VM from backup or replica, or migrate a VM from another cluster to the cluster that runs VirtuCache and if you don’t see the new VM in the VirtuCache GUI, try the below three tasks before you open a ticket. 1….
VMware vSphere Replication is functionality in VMware that allows Vmware customers to replicate their VMs to another location for disaster recovery purposes. vSphere replication can work standalone or along with VMware Site Recovery Manager. vSphere replication uses agents in ESXi hosts to track changed blocks using internal vSCSI interfaces in VMware…