SCSI reservation on the disks did not allow the filesystem to be mounted.
Clear the keys from the disks
#vxdisk -qeo alldgs list | awk '{print "/dev/rdsk/"$6}' > /tmp/disks
# vxfenadm -s all -f /tmp/disks
# vxfenadm -r all -f /tmp/disks
[2] Clear keys
vxfenadm -a -k tmp -f /tmp/disks
vxfenadm -c -k tmp -f /tmp/disks
[3] Check keys again
vxfenadm -s all -f /tmp/disks
UX:vxfs mount: ERROR: V-3-23740: CVM reservation failed for /dev/vx/dsk/appdg/vol_u02.