Always check your current and free lvol size before increasing so you can keep track and notice the differents.
We take a scenario where I would want to increase my /dev/vg00/lvol10 to 1GB
- umount /dev/vg00/lvol10
- lvextend -L 1024 /dev/vg00/lvol10
- extendfs -F vxfs /dev/vg00/lvol10
- mount /dev/vg00/lvol10 /myfolder
bdf command to check your increased lvol size.