Thanks for your suggestion. NFS is the last option I thought though It may be little awkward according to my current architecture. I have following queries:
1. If I go with only GFS, will it work while device is logical volume? I don't want to go with clvm as it requires kernel compilation.
2. Will it be sufficient if I build with GFS SRPM? Compilation of kernel will not be approved.
3. Can we make 'sync, drop_cache' technique more predictable?
4. I have seen one option in mount -o dio. What this option actually doing? Will be helpful?