Setup guide

■ Concurrent I/O and metadata operations
■ Number of I/O threads and processes in use at a given time
NOTE Standard filesystems tuned for a specific file format can under-perform for
other file formats. For instance, a filesystem optimized and capable of delivering
real-time performance for 2K 10-bit DPX files delivers lower real-time performance
for SD media.
Filesystem performance progressively decreases over time, depending on
various factors, such as fragmentation, fill rate, and concurrent use by several
applications.
This chapter provides basic usage and maintenance guidelines to help you
keep the performance of your standard filesystem at a steady level.
Terminology and Concepts
Before reading this chapter, familiarize yourself with the following concepts.
Fragmentation is a phenomenon that consists of a file
being broken into several blocks, which are stored in
Fragmentation
non-contiguous sectors on the disk. This decreases
filesystem performance, as it takes a lot of time to retrieve
and reassemble the scattered pieces of the file before
making it usable.
This principle states that files used in the context of the
same application or procedure (for example, consecutive
Locality of
reference
frames in a timeline) should be as close to each other as
possible on the disk, in order to minimize seek times
between two successive I/O operations. Locality of reference
is good in the case of frames written on an empty partition,
and decreases as the filesystem fills up and becomes
fragmented.
Multi-threaded I/O is the use of multiple parallel I/O
threads within a disk read process. This method allows the
Multi-threaded
I/O
RAID array to optimize the fetching of multiple blocks of
data.
Visual Effects and Finishing Standard Filesystem Maintenance | 201