Identifying Flash Virtual Disks

Guest operating systems can identify virtual disks that reside on flash-based datastores as flash virtual disks.

To verify if this feature is enabled, guest operating systems can use standard inquiry commands such as SCSI VPD Page (B1h) for SCSI devices and ATA IDENTIFY DEVICE (Word 217) for IDE devices.

For linked clones, native snapshots, and delta-disks, the inquiry commands report the virtual flash status of the base disk.

Operating systems can detect that a virtual disk is a flash disk under the following conditions:

• Detection of flash virtual disks is supported on ESXi 5.x and later hosts and virtual hardware version 8 or later.
• Detection of flash virtual disks is supported only on VMFS5 or later.
• If virtual disks are located on shared VMFS datastores with flash device extents, the device must be marked as flash on all hosts.
• For a virtual disk to be identified as virtual flash, all underlying physical extents should be flash-backed.