Which SSD Make/Model to buy? If you are buying new ESXi servers, then order the servers with at least one U.2 slot for an NVME SSD. Our recommended NVME SSD in the U.2 form factor is the Intel P4610 SSD. As you can see from this link on the Intel…
SSD
If you plan on using NVME SSD as a cache device and you don’t have a NVME slot in the ESXi host. You could either buy a NVME SSD in PCIe form factor like the Intel P4600 2TB or Samsung PM1725 1.6TB. Both these SSDs are highly recommended, but they…
The maximum SSD capacity supported as cache device in VirtuCache is 6TB per host, and 384TB SSD capacity across an ESXi cluster.
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…
Following up from this KB article on this topic, if the SSD was being used by Infinio, Flashsoft, or PernixData, then it will have a partition on it, that might not be visible from the ‘Erase Partition’ option for that SSD in the vcenter GUI. Below are the steps you…
VirtuCache and VFRC cannot co-exist on the same ESXi host or cluster, and there is no reason to use VFRC or Host Swap cache if VirtuCache is being used, since VirtuCache provides more functionality than VFRC or Host Swap Cache. Functionality of VFRC or Host Swap Cache is a subset…
Sandisk FusionIO PCIE flash cards like IoDrive2 are some of the best SSDs on the market, comparable to newer NVME cards. Especially for low queue depth workload like VDI, they are even better performing. However please keep in mind that they use a lot of memory on the host. 20GB…
Importance of Queue Depth – Higher the Queue Depth, Higher the IOPS Queue Depth is a number assigned by the device vendor to their storage device that advertises to the component above the device in the storage IO path, the maximum number of IO requests the device can process simultaneously….
If you get an error of the type: “Failed: Assign SSD for Caching on host” while trying to assign an SSD to VirtuCache, then its most likely because of any of the below reasons. 1. The SSD is being used as a VMware Datastore. If so, you will have to unmount…
SSD failure in VirtuCache is handled differently in ‘Write-Through’ (accelerates only reads) and ‘Write-Back’ (accelerates reads and writes) caching policies. In both Write-Through and Write-Back caching policies, read caching works in the same way. Frequently and recently used reads are copied from backend storage to in-host SSD. So if the…