DNS resolution is case-insensitive everywhere. Please read https://www.ietf.org/rfc/rfc1035.txt chapter "2.3.3. Character Case" for details.
In our case when the hostname is "yuval-pc" and XAP_MANAGER_SERVERS=YUVAL-PC
When starting the agent with a manger (./gs-agent.sh --manager-local), the agent can't start with the following error:
2017-09-11 14:14:05,658 ZK SEVERE [com.gigaspaces.zookeeper] - Current host [yuval-pc/127.0.0.1] is not part of the configured zookeeper ensemble [YUVAL-PC:2888:3888]
Use the same case for the manager and the hostname.