Caching on VMware ESXi
Caching is used to accelerate storage performance on VMWare ESXi hosts. Several different approaches to perform caching on VMware ESXi were commercially available. Over the years, VirtuCache has emerged as the most preferred caching solution for VMware deployments.
VirtuCache caches all VM reads and writes to in-host cache, and it protects against data loss in case of host failure by mirroring the write cache to other ESXi hosts in the same VMware cluster. Caching is fully automatic, with cache capacity dynamically allocated to VMs based on usage patterns.
It is an easy to use downloadable software certified by VMWare. It requires no storage and host reconfiguration. And no ongoing administration is required.
How to use caching in VMware ESXi using VirtuCache
Here is a quick summary:
- Download the trial
- Install the driver on the ESXi hosts. You can use Vmware Update Manager / Lifecycle Manager. Placing ESXi hosts in maintenance mode is not required
- Deploy the virtual appliance (OVA)
- Use the browser to connect to the VirtuCache manager virtual appliance and configure caching
- Specify the Replication Network. This network is used for mirroring the cached writes. It is also used to maintain cache coherency across the cluster.
- Select the caching media on per-ESXi host basis. Use spare host RAM if available; otherwise, use SSDs for caching. You can also use a combination of RAM and SSD
- Specify the caching policy for a group of VMs by assigning the policy on a datastore level. You can then override the policy for individual VMs. Caching policy can either be Write-back (write-acceleration) or Write-through (read-only caching)
The following screencast show in detail how to use caching in VMware ESXi using VirtuCache: