vsphere-esxi-vcenter-server-55-storage-guide

vSphere Storage5 Select disks to be used for Virtual SAN.On each host, you must select at least one SSD and one or multiple HDDs. If you select several SSDs,the number of HDDs must be equal to the number of SSDs, or greater.Virtual SAN claims the disks that you select and organizes them into default disk groups that back theVirtual SAN datastore.Use Manual Method to Claim Disks for Virtual SANWhen Virtual SAN is enabled in the manual mode for the host cluster, you can use a manual method ofcombing specific SSDs with specific HDDs and creating user-defined disk groups on a particular host.This method contrasts with the semi-automatic claiming of disks for Virtual SAN, where you can selectmultiple disks to be consumed by Virtual SAN, but do not organize them into groups. Instead, after youselect the disks, Virtual SAN creates default disk groups for you. In contrast, when you manually create adisk group, you can be more specific and organize selected disks into disk groups. You first select an SSDand then add up to seven HDD disks of your choice to form a disk group. Virtual SAN supports up to fivedisk groups per a host. The disk groups that you create belong to the particular host where the disks reside,and you cannot reassign the groups to another host.When you create a disk group, your main consideration should be the ratio of SSD to HDD capacity.Although the ratios depend on use cases and workloads, the best practice is to use 1:10 ratio of the SSD toHDD capacity.Procedure1 Browse to the Virtual SAN cluster in the vSphere Web Client navigator.2 Click the Manage tab and click Settings.3 Under Virtual SAN, click Disk Management.4 Click the Create a new disk group icon.5 Select an SSD disk, and then select one or multiple non-SSD disks.For each disk group, you can select only one SSD and up to six non-SSD disks.6 Click OK.The new disk group appears on the list.Add a Disk to the Disk GroupWhen you use Virtual SAN in manual mode, you can add local disks to existing disk groups.Procedure1 Browse to the Virtual SAN cluster in the vSphere Web Client navigator.2 Click the Manage tab and click Settings.3 Under Virtual SAN, click Disk Management.4 Select the disk group, and click the Add a disk to the selected disk group icon.5 Select a disk to add and click OK.The disk appears on the list of disks that belong to the disk group.184 VMware, Inc.