Now vFlash (aka vFlash Read Cache) without physical SSD
The vSphere Flash Read Cache is a flash-based storage solution that pools multiple flash- based devices into a vSphere Flash Resource, as illustrated in Figure 1. It is used to accelerate read-intensive workloads and improve virtual machine performance. This feature is also supported with vMotion, HA, and DRS.
vSphere Flash Read Cache
- Vsphere 5.5 (Both esxi and vcenter)
- 1 SSD Drive per host
- VM Version 10 to configure the vFlash read cache
- vFlash configured for each host
Note: This process to test in the LAB environment to check the vFlash feature, not applicable for production environment.
Steps for creating the Virtual SSD:
- Create a physical local virtual disk on the ESXi Host(s) that you want to enable vFlash. Ensure that the local virtual SSD size doesn’t exceed the size of the physical ESXi host’s local virtual disk.
- Locate the ESXi host’s local virtual disk path (e.g. mpx.vmhba1:C0:T1:L0).
- Open a Secure Shell (SSH) session to each ESXi host you’ll be configuring with a local virtual SSD.
- Convert the physical local virtual disk to a local virtual SSD. Utilize the following esxcli command strings for the conversion.
# esxcli storage nmp satp rule add -s VMW_SATP_LOCAL -d mpx.vmhba1:C0:T1:L0 -o enable_ssd
Next, verify the SATP rule creation:
The Storage Array Type Plugin (SATP) will allow your storage I/O to be load balanced properly by vCenter while using this new virtual disk. Here’s the code that creates an SATP rule and enables the SSD string:
# esxcli storage nmp satp rule list | grep enable_ssd
Next comes reclamation of the new virtual SSD, to enable application of the SATP rule:
# esxcli storage core claiming reclaim -d mpx.vmhba1:C0:T1:L0
Finally, confirm that the new virtual SSD has been created:
# esxcli storage core device list -d mpx.vmhba1:C0:T1:L0
Once you verify that the Is SSD entry is true, the local disk is now a virtual one. You can use the GUI to add the Virtual SSD.
Now Virtual SSD has been created and added to ESXi hosts.
Now that your virtual SSD is created and verified, you can add it to your ESXi host(s) and start using the vFlash feature. vFlash is easy to set up – just configure it in the vCenter Web client.
Setting Up vFlash:
- In the vSphere Web Client, navigate to the host.
- Click the Manage tab and click Settings.
- Under Virtual Flash, select Virtual Flash Resource Management, then click Add Capacity. From the list of available SSD devices, select the newly-created local virtual SSD drive to use for virtual flash and click OK.
- Now we have cache enabled on host as below shows a SSD created with VFFS file system.