This is very much possible. Part of the reason access zones was created was just this use case of having different ADs that have no trust between them.  You can have 5 zones per authentication type (AD/LDAP/NIS). The Isilon OneFS 7.2 Technical Specifications Guide has lots of details around this kind of these and be found on the support.emc.com site by doing a search for the document name.  1) I want to keep Customer 1 in system zone and shares will be intact That is fine, but then you don't want to remove the auth providers and shares on the system zone.  2) Without removing the system access zone can we create remaining 3 access zones ? is that possible ? Yes. You can have up to 5 zones using AD as the authentication provider.  They can be trusted or not trusted.
Hello  We are planning to implement the Mulitency on isilon cluster currently we have single zone (system zone ) with 3 pools. We are planning to configure the multitency with 4 internal customer , these customer will have 4 AD servers(dedicated to the customer). I have gone through the KB article Article Number:000016464 Version:5 As per the KB Modify the System zone to remove All Auth Providers: isi zone zones modify System --all-auth-providers=No Modify the System zone to remove All SMB Shares: isi zone zones modify System --all-smb-shares=No  This will remove the System zone access , that  user access will be lost . Question: 1) I want to keep Customer 1 in system zone and shares will be intact 2) Without removing the system access zone can we create remaining 3 access zones ? is that possible ?
Access Zones config