Setup guide

Your Visual Effects and Finishing applications use multi-threaded asynchronous
direct I/O when capturing, playing back, and performing other I/O intensive
operations.
Make sure that any third-party application you use in conjunction with your
Visual Effects and Finishing application or to handle your media files uses
direct I/O. This prevents needless CPU-intensive in-memory data copying,
thus maintaining optimum storage performance and freeing resources for
your Visual Effects and Finishing application.
Enabling Media Pre-allocation
By default, disk space for video files is allocated on-the-fly as the files are
rendered or written. Concurrent I/O operations from multiple clients or
background processes can generate frames with poor locality of reference,
which leads to clip fragmentation and decreases playback performance.
To prevent this problem, Stone and Wire provides media file pre-allocation
mechanisms that reserve the necessary space on the disk before the actual
writing of the media files takes place. Pre-allocation reserves as many available
contiguous disk sectors as needed for the file sequence to be written.
Depending on the filesystem you are using, you may choose between two
media pre-allocation methods.
The disk space needed for the file is allocated and filled with
zeroes. On most filesystems, the performance impact of this
operation is as serious as when writing the actual file.
FALLOCATE
The disk space needed for the file is reserved, but not written
to. The apparent size of the frame remains zero. This
RESERVE
operation is much faster than FALLOCATE, but is supported
only on certain filesystems, such as XFS.
By default, pre-allocation is turned off in Stone and Wire (the method is set
to NONE). In order to enable it, you must modify a parameter in the
stone+wire.cfg configuration file.
NOTE This is not a global setting. Pre-allocation must be individually enabled for
each partition.
To enable media pre-allocation for a partition:
1 Open the/usr/discreet/sw/cfg/stone+wire.cfg file in a text editor.
212 | Chapter 6 Advanced Configuration and Troubleshooting