ESXi 5.0 host disconnects due to CPU crossdup error

If a host is disconnected in vCenter and you cannot reconnect the host and you see the following entries in the /var/log/vmkwarning file:

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 675: Failed to crossdup fd 13, /vmfs/devices/char/vob/External type CHAR: Busy

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 675: Failed to crossdup fd 14, /vmfs/devices/char/vob/iScsi type CHAR: Busy

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 675: Failed to crossdup fd 15, /vmfs/devices/char/vob/Migrate type CHAR: Busy

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 675: Failed to crossdup fd 16, /vmfs/devices/char/vob/PageReti type CHAR: Busy

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 675: Failed to crossdup fd 17, /vmfs/devices/char/vob/Visorfs type CHAR: Busy

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 675: Failed to crossdup fd 18, /vmfs/devices/char/vob/Hardware type CHAR: Busy

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 675: Failed to crossdup fd 19, /vmfs/devices/char/vob/Vfat type CHAR: Busy

2013-07-05T06:54:02.084Z cpu7:7757089)WARNING: UserObj: 3232: Unimplemented operation on 0x410028907210/SOCKET_UNIX_SERVER

It can be fixed by following this KB:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2031894

So, SSH to the host and edit the file (/etc/vmware/vpxa/vpxa.cfg) using vi text editor.

The following line should be changed, the value should be increased to 256 from originally 128:

'ThreadStackSizeKb'256'/ThreadStackSizeKb'

Vpxa.cfg is read-only so you can change it with:

# chmod 744 vpxa.cfg

And when done – to get file back to read only:

# chmod 444 vpxa.cfg

Restart the vpxa service and reconnect the host.

# /etc/init.d/vpxa restart