README
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reflink
Perform reflink operation on compatible filesystems (btrfs or xfs).
What is a reflink?
There are a number of type of links existing on Linux:
- symlinks
- hardlinks
- reflinks
Reflinks are a new kind of links found in btrfs and xfs which act similar to hard links, except modifying one of the two files will not change the other, and typically only the changed data will take space on the disk (copy-on-write).
Can I use reflinks?
A machine needs to have a compatible OS and filesystem to perform reflinks. Known to work are:
- btrfs on Linux
- xfs on Linux
Other OSes have similar features, to be implemented in the future.
- Windows has
DUPLICATE_EXTENTS_TO_FILE - Solaris has
reflink - MacOS has
clonefile
Usage
err := reflink.Always("original_file.bin", "snapshot-001.bin")
// or
err := reflink.Auto("source_img.png", "modified_img.png")
reflink.Always will fail if reflink is not supported or didn't work for any reason, while reflink.Auto will fallback to a regular file copy.
Notes
- The arguments have been put in the same order as
os.Linkoros.Renamerather thanio.Copyas we are dealing with filenames.
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( ErrReflinkUnsupported = errors.New("reflink is not supported on this OS") ErrReflinkFailed = errors.New("reflink is not supported on this OS or file") )
ErrReflinkUnsupported is returned by Always() if the operation is not supported on the current operating system. Auto() will never return this error.
Functions ¶
func Always ¶
Always will perform a reflink operation and fail on error.
This is equivalent to command cp --reflink=always
func Auto ¶
Auto will attempt to perform a reflink operation and fallback to normal data copy if reflink is not supported.
This is equivalent to cp --reflink=auto
Types ¶
This section is empty.
Source Files