Does ESXi server power down physical hard disks in ESXi server when no disk activity is detected? Or, when very little disk activity is happening it might get cached instead of spinning up the hard drive for a small write?
If the answer is yes, how can this behavior be controlled/configured ?
As a side note, I know that there is a way (officially unsupported) to attach physical disks to Guest operating systems as a RAW disk rather than a virtual disk. I wonder if the Guest operating system would then have any direct control over powering down the physical disk based on the Guest operating system's power management settings.
- Reason for asking:
I was toying with the idea of using a spare hard drive as an additional backup target. Since that hard drive would only ever see activity when there is a backup job running, the rest of the time there would be no activity. I wondered if ESXi or a Guest OS (via raw disk, see above) could power it down to save power and wear and tear on the disk.