6.0 HP X9000 File Serving Software File System User Guide (TA768-96043, October 2011)

protocols must mount the file system from a file serving node. All requests are sent to the
mounting server, which performs the required routing.
5. A client request can be made for a file on a segment that is either owned by the server, owned
by another server but accessible by this server over the SAN, or owned by another server and
not accessible by this server over the SAN. In the second scenario, the server obtains the
relevant metadata from the owning server and performs the I/O directly over the SAN. In the
third scenario, the I/O is performed through the owning server over the IP network.
File system building blocks
A file system is created from building blocks. The first block comprises the underlying physical
volumes, which are combined in volume groups. Segments (logical volumes) are created from the
volume groups. The built-in volume manager handles all space allocation considerations involved
in file system creation.
Configuring file systems
You can configure your file systems to use the following features:
• Quotas. This feature allows you to assign quotas to individual users or groups, or to a directory
tree. Individual quotas limit the amount of storage or the number of files that a user or group
can use in a file system. Directory tree quotas limit the amount of storage and the number of
files that can be created on a file system located at a specific directory tree. See “Setting up
quotas” (page 22).
• Remote replication. This feature provides a method to replicate changes in a source file system
on one cluster to a target file system on either the same cluster or a second cluster. See “Using
remote replication” (page 100).
• Data retention and validation. Data retention ensures that files cannot be modified or deleted
for a specific retention period. Data validation scans can be used to ensure that files remain
unchanged. See “Managing data retention and validation” (page 112).
• X9000 software snapshots. This feature allows you to capture a point-in-time copy of a file
system or directory for online backup purposes and to simplify recovery of files from accidental
10 Using X9000 Software file systems