Hot adding a virtual disk in ESXi 5.5 removes the multi-writer flag (2078540)

Symptoms

• When a virtual disk is added while the virtual machine is powered on, the pre-populated multi-writer flag is removed from the.vmx file.
• The hot add fails with file lock errors though the .vmx file contains scsix:x.sharing=Multi-Writer.
• Hot addition of disks to Oracle RAC fails with file lock errors.

Resolution

This is a known issue affecting ESXi 5.5.

 

Currently, there is no resolution.

To work around this issue, power off the virtual machine and then add virtual disks.

 

Source:-

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2078540&src=vmw_so_vex_ragga_1012