Error Message:

VCS WARNING V-16-20011-5502 (cluster01) CFSMount:cfsmount50:online:Mount Failed on this Node MountOptions -t vxfs -o cluster,suid,rw Block Device /dev/vx/dsk/dg01/vol01 : MountPoint /data01
VCS WARNING V-16-20011-5508 (cluster01) CFSMount:cfsmount01:online:Mount Error : UX:vxfs mount.vxfs: ERROR: V-3-20: Input/output error

 

The above error occurred because of the /data01 still mounted with I/O error, and you can verify it using df:

# df -k | grep error
df: `/data01': Input/output error

Solution:

Force umount the disabled filesystem
# umount -f /data01 // for linux
# umount -o force /data01 // for Solaris

You might need to fsck as there might be some hardware issue which caused filesystem disable.
# fsck -t vxfs /dev/vx/rdsk/dg01/vol01

Then, startup cluster and bring up CFS resource online.

 

Mount error : ux:vxfs mount.vxfs: error: v-3-20: input/output error