VSAN-Troubleshooting-Reference-Manual

Diagnostics and Troubleshooting Reference Manual – Virtual SAN
Observations when a flash device fails
In this example, the flash cache device (in this case an SSD) was removed from the
disk group. The events were similar to what was observed with a magnetic disk
removal. Virtual SAN determines that the device has a permanent failure, enters
APD state, and the device being marked as permanently inaccessible. Note however
that all the magnetic disks in the disk group also go offline.
When a flash cache device in a disk group is impacted by a failure, the whole of the
disk group is impacted. The disk group status in the vSphere web client shows the
overall disk group is now “Unhealthy”. The status of the magnetic disks in the same
disk group shows “Flash disk down”.
If the timeout expires before the original device has been reinserted in the host, the
rebuilding of components in the disk group takes place.
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