Oracle Exalogic Elastic Cloud, Руководство пользователя

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9
Configure NFS Version 4 on Exalogic
This chapter describes how to set up and configure Network File System (NFS)
Version 4 (NFSv4) on Oracle Exalogic.
It contains the following topics:
• Overview
• Verify the NIS Setting on Exalogic
• Configure the Storage Appliance
• Configure an Exalogic Linux Compute Node to Use NFSv4
• Create NFSv4 Mount Points on Oracle Linux
9.1 Overview
Oracle Exalogic is a multihomed system where multiple IP addresses are configured
on the InfiniBand network interface. NFSv4 addresses file locking problems on
multihomed systems, such as Exalogic. The file locking problem occurs when NFSv3 is
used.
9.1.1 NFSv3
NFSv3 is a stateless protocol. NFS clients do not maintain the state between requests;
the clients rely on the Network Lock Manager (NLM) protocol to support file locking.
There are known limitations on the NLM based locking, and NFSv3 it can cause lock
ownership issues under certain multihomed system configurations, where the source
IP addresses are not deterministic between lock and unlock requests.
9.1.2 NFSv4
Unlike NFSv3, NFSv4 is a stateful protocol. An NFS client obtains a client ID assigned
during the initial negotiation phase and uses it for all subsequent requests. With the
use of Client ID, the client IP address is not used in the file locking process. Therefore,
the file locking problem on Exalogic does not occur when NFSv4 is used. In addition,
with locking built into the protocol, NFSv4 provides better lock performance than
NFSv3.
9.1.3 Naming Service
NFSv4 requires a naming service, such as Network Information Service (NIS) or
LDAP, for ID mapping. You can continue to use the naming service on your existing
network. The naming service is not related to the file locking problem.
Configure NFS Version 4 on Exalogic 9-1