Query on Asmlib

I have Oracle Linux running on vmware hosting an Oracle database with ASM (single instance). There isn't any operating system device persistence and therefore whenever my OS reboots, the disk number changes and ASM doesn't mount the disks even after I set diskstring parameter. I do not have OS multipathing since I have multipath on storage. Disks are configured using asmlib only. I understand asmlib was introduced to ease the management of disks (addition of disks to the cluster) but wasn't it also designed to prevent this from happening? How can I prevent on server reboots, the disk major and minor number changes and diskgroups are not getting mounted. Will add more information if required.