ORA-15032: not all alterations performed ORA-15063: ASM discovered an insufficient number of disks for diskgroup

Issue:

We had server reboot, After that we are not able to bring back the ASM disk,
We are getting below error.

[root@Node-1 bin]# ./crs_start ora.ASM_FRA01.dg
Attempting to start `ora.ASM_FRA01.dg` on member `za-fdbs-dr-01`
CRS-5017: The resource action "ora.ASM_FRA01.dg start" encountered the following error:
ORA-15032: not all alterations performed
ORA-15017: diskgroup "ASM_FRA01" cannot be mounted
ORA-15063: ASM discovered an insufficient number of disks for diskgroup "ASM_FRA01"


Start of `ora.ASM_FRA01.dg` on member `Node-1` failed.
Attempting to stop `ora.ASM_FRA01.dg` on member `Node-1`
Stop of `ora.ASM_FRA01.dg` on member `Node-1` succeeded.
CRS-0215: Could not start resource 'ora.ASM_FRA01.dg'.


Solution:

We had multipath configured in the server,So we blacklisted the ASM lun's in the /etc/multipath.conf.
then we mount the disk in ASM.

Steps
++ To find list of multipath disk
[root@Node-1 ~]#multipath -ll

mpath5 (360060160260d2900621e1d393121e411) dm-5 DGC,RAID 5
[size=500G][features=1 queue_if_no_path][hwhandler=1 emc][rw]
\_ round-robin 0 [prio=6][active]
 \_ 15:0:0:4 sdad 65:208 [active][ready]
 \_ 16:0:0:4 sdag 66:0   [active][ready]
 \_ 18:0:0:4 sdak 66:64  [active][ready]
 \_ 21:0:0:4 sdal 66:80  [active][ready]
 \_ 22:0:0:4 sdam 66:96  [active][ready]
 \_ 20:0:0:4 sdan 66:112 [active][ready]

++ Black list in /etc/multipath.conf the wwid.

blacklist {
        wwid 360060160260d2900d2f242623020e411
  
++ Restart the services.

service multipathd restart

++ Now mount the disk in ASM.

root@Node-1 bin]# ./crs_start ora.ASM_FRA01.dg
Attempting to start `ora.ASM_FRA01.dg` on member `Node-1`
Start of `ora.ASM_FRA01.dg` on member `Node-1` succeeded.