I found a problem with my disks on my Oracle servers.
All of them are virtual machines on VMWare server and the operating system is SLES 12.
As I used to do in SLES 11, I create separate disks to Linux filesystem, Oracle software files and Oracle database files. I configured the disks for Oracle database files to use ASM instance, so I didn't format them and I assigned permissions to grid infrastructure user. The ASM instance was createad correctly and it worked without problems afterwards.
The problem became after some patches installation. The system reboot and then, the diskgroups of the ASM instance didn't start anymore. Looking to logs I saw that the diskgroups had problems to mount the disks configured at installation time. First of all, I thoguht that some disks might be corrupt, but then I found out the real problem: the disks devices changed their names.
Graphically the change was the next:

Has anybody found the same problem? How can I revert this to the original configuration?
Thanks in advanced