Linux command
fallocate 命令
文件
复制后可按需替换文件名、目录或参数。
常用示例
Allocate
fallocate -l 700M path/to/file
Shrink
fallocate -c -l 200M path/to/file
Example
fallocate -c -o 100M -l 20M path/to/file
说明
fallocate preallocates or deallocates space to a file. Unlike writing zeros, fallocate uses filesystem-specific operations to quickly allocate space without initializing the data, making it very fast for creating large files.
参数
- -l, --length _size_
- Length of the range to allocate or deallocate
- -o, --offset _offset_
- Offset of the range from the beginning of the file
- -c, --collapse-range
- Remove a range from the file without leaving a hole
- -d, --dig-holes
- Detect and convert zero blocks to holes
- -p, --punch-hole
- Deallocate space (create a hole) in the file
- -z, --zero-range
- Zero a range but keep space allocated
- -n, --keep-size
- Maintain apparent file size when extending allocation
FAQ
What is the fallocate command used for?
fallocate preallocates or deallocates space to a file. Unlike writing zeros, fallocate uses filesystem-specific operations to quickly allocate space without initializing the data, making it very fast for creating large files.
How do I run a basic fallocate example?
Run `fallocate -l 700M path/to/file` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does -l, --length _size_ do in fallocate?
Length of the range to allocate or deallocate