Shared logarch across multipe db2 HADR instances
We are using a HADR environment with only one standby. Our log files are shared using a simple NFS. That works fine for us, but the two servers are located next to each other. 

I assume if a NFS share works with standby 30 km away depends on the network connection (speed and reliability) to the external location. 

We are going to locate our primary and standby now in two separate buildings, but they are only a few hundred meters away. For this we will have two SAN systems that are mirrored, one in each building. So the transfer of the data will be handled by the SAN system transparent to the DB2 servers. The two building are connected by fibre channel cables.  

We do this for security reasons as it would make no sense to have the SAN system located in building 1 together with the primary while the standy is located in building 2 but has to access the SAN in building 1. If the data center in building 1 is going down, the standby in building 2 will be of no use without SAN access. 

How you should setup your environment highly depends on your requirements and goals. Do you want to accelerate the your database access or do you want to increase the security?