You shouldn't need to change that. You should be able to use what's already there:
# kinit administrator
Password for administrator@NTAP.LOCAL:
# mount -o username=administrator,sec=krb5 -t cifs //companyb/share /mnt/client2
# mount | grep companyb
//companyb/share on /mnt/client2 type cifs (rw,relatime,vers=default,sec=krb5,cache=strict,username=administrator,uid=0,noforceuid,gid=0,noforcegid,addr=10.x.x.x,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=1048576,wsize=1048576,echo_interval=60,actimeo=1)
If you need a different name, that's going to be controlled via the netbios name.
ontap9-tme-8040::*> cifs server show -vserver COMPANYB
Vserver: COMPANYB
CIFS Server NetBIOS Name: COMPANYB
NetBIOS Domain/Workgroup Name: NTAP
Fully Qualified Domain Name: NTAP.LOCAL
Organizational Unit: CN=Computers
Default Site Used by LIFs Without Site Membership:
Workgroup Name: -
Kerberos Realm: -
Authentication Style: domain
CIFS Server Administrative Status: up
CIFS Server Description:
List of NetBIOS Aliases: -
That field is not controlled by ONTAP, but by the AD domain.
If you want to specify a new name for the clients to use, use the NETBIOS alias.
ontap9-tme-8040::*> cifs server add-netbios-aliases -vserver COMPANYB -netbios-aliases ALIAS
ontap9-tme-8040::*> cifs server show -vserver COMPANYB
Vserver: COMPANYB
CIFS Server NetBIOS Name: COMPANYB
NetBIOS Domain/Workgroup Name: NTAP
Fully Qualified Domain Name: NTAP.LOCAL
Organizational Unit: CN=Computers
Default Site Used by LIFs Without Site Membership:
Workgroup Name: -
Kerberos Realm: -
Authentication Style: domain
CIFS Server Administrative Status: up
CIFS Server Description:
List of NetBIOS Aliases: ALIAS
Add the alias to DNS with the same IP address using a CNAME record. Make sure the client can resolve it. For Kerberos, it should point to the DNS record that associates with the CIFS server name.
# nslookup alias
Server: 10.x.x.y
Address: 10.x.x.y#53
alias.ntap.local canonical name = companyb.ntap.local.
Name: companyb.ntap.local
Address: 10.x.x.x
You also would need to add an SPN for that alias.
PS C:\> setspn /L COMPANYB
Registered ServicePrincipalNames for CN=COMPANYB,CN=Computers,DC=NTAP,DC=local:
cifs/alias.ntap.local
cifs/alias
HOST/companyb.ntap.local
HOST/COMPANYB
Then you can mount using the alias:
# mount -o username=administrator,sec=krb5 -t cifs //alias/share /mnt/client2
# mount | grep alias
//alias/share on /mnt/client2 type cifs (rw,relatime,vers=default,sec=krb5,cache=strict,username=administrator,uid=0,noforceuid,gid=0,noforcegid,addr=10.x.x.x,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=1048576,wsize=1048576,echo_interval=60,actimeo=1)
