Repeated "Unable to register file system" with "for quesce timeout notifications: Inappropriate ioctl for device" on vSAN cluster nodes

Products

• VMware vSAN

Issue/Introduction

"Unable to register file system ########-####-####-####-############ for quesce timeout notifications: Inappropriate ioctl for device" appears repeatedly in vmkernel.log on vSAN cluster nodes.

Note: "########-####-####-####-############" is a vSAN namespace object UUID.

The message repeats even if: 

• The object is healthy and no access problem on that. 
• vSAN Health status: all green. 
• No alert on the vSAN nodes. 

Environment

VMware vSAN

Cause

The "quesce" ioctl is called at a file system layer and sent to an underlying device. In this case, it is a vSAN namespace object. 
On the other hand, vSAN does not support that ioctl. 
Therefore, the ioctl is expected to fail on vSAN objects. 

Resolution

The messages are harmless and can be safely ignored.