yes if one SP fails then the peer SP takes over its services

Please see the Unity High Availability White paper for details

The same also in this case ?

not sure I understand what you mean

you are showing two Unity systems - they are Independent of each other

just because on Unity1 SPA failed over to SPB doesnt cause a similar failover on Unity2 and vice versa

Hi

This image mean the Unity replicating from production site to destination site.

----environment------

NAS Server1 is SPA

NAS Server3 is SPB

NAS Server1(owner SPA)→Dest_NAS Server1(owner SPA)

NAS Server3(owner SPB)→Dest_NAS Server3(owner SPB)

------------------------------

I want to know below.

For example.

When destination site SPA was out of order, will production site SPA is failovered ?

no - there is no reason for that