This topic describes the requirements for the shared file system
in a cluster.
All nodes in the cluster
must have access to a shared file system on which the data files are stored.
The leader node must have write access, and the follower nodes must have read
access.
On Windows, it is recommended to utilize a file system that uses the
CIFS (also known as SMB) protocol. On Linux, it is recommended to use NFS.
File system size. You can
start a cluster with a single node that serves both as the leader and a
follower node. As you add additional follower nodes, file system size
requirements (as measured by the high-water mark parameters for shared storage)
increase modestly and do not increase proportionally to the number of follower
nodes.
Performance. Even in a
single-node cluster, storing data files on remote disks affects node startup
time and performance associated with processing of data files updates. In a
multi-node cluster, all nodes are accessing the data files at the same time.
This coordinated access may affect performance for the network or shared file
system, especially when large updates are accessed for the first time.