Chapter 1 Introduction 1-5
With the exception of the APIs for the MSM and CM, the workings of the server’s
software components are largely invisible to the user. This is particularly true of the
MFS, access to which is exclusively throughout the MSM and CM.
The Sun MediaCenter software offers the following features:
Guaranteed stream delivery rate
Once a stream is accepted for delivery, the server delivers the stream contents at a
guaranteed rate until the end of the stream content is reached, the server is asked
to stop playing the stream, or server hardware fails.
Independent streams
Delivered streams are independent: they can be stopped and started individually;
output streams might all be playing simultaneously from different portions of the
same content stream or from different content streams.
Online loading
The server maintains delivery of streams as the highest priority task, so that as
the server approaches its maximum bandwidth in stream delivery, any content
loading taking place will slow and, at some point, stop, until such time as the
server recovers sufficient resources to resume loading. (Note that you cannot load
content if the server is reading data from the parity disk, which occurs following
a disk failure.)
Playthrough
The server software supports a playthrough capability wherein a Sun
MediaCenter server can deliver streams from a title as that title is stored. A given
piece of content can be played from the server only five seconds after storage of it
has begun.
The following subsections describe the components of the Sun MediaCenter
software.
1.3.1 Media File System (MFS)
The MFS is designed to deliver multimedia data from an array of attached disks to
an output network. In addition to providing the foundation for all of the features
listed above, the file system supports:
Recovery from single-disk failures
The MFS will recover from a single disk failure after a small start-up interval (less
than 10 seconds). It uses a strategy similar to RAID-4. The number of content
disks for each parity disk varies with the disk subsystem used for a particular
server model.