Editing XFS (section)

===Delayed allocation===
{{Main|Delayed allocation}}

XFS makes use of [[lazy evaluation]] techniques for file allocation. When a file is written to the buffer cache, rather than allocating extents for the data, XFS simply reserves the appropriate number of file system blocks for the data held in memory. The actual block allocation occurs only when the data is finally flushed to disk. This improves the chance that the file will be written in a contiguous group of blocks, reducing [[file system fragmentation|fragmentation]] problems and increasing performance.