Collection of command-line tools for taking advantage of modern Linux file system CoW features.

Kleb is a tool for concatenating multiple source files to a single file without copying the contents on disk. It can benefit reflink (range copy) support on the file system.

Usage: kleb [OPTION?] FILE... TARGET | -t TARGET FILE...

See full usage by running kleb --help.

The rationale behind this tool is to allow files (such as disk images) to be stored in fragments during transfer but allowing space and time efficient merge of the results.

NB! To benefit from reflink feature, on Btrfs the file "seams" need to be at multiples of the fundamental block size of the file system. And naturally, the files need to be on a same file system. Otherwise, warning is printed and a regular copy is performed. To see the block size of current directory, you may stat -fc %S ..

Does the opposite than Kleb. Splits given source file into fragments without copying contents on disk.

Usage: trenn [OPTION?] -s SIZE FILE

The size must be a multiple of the fundamental block size of the file system. It accepts SI and binary multipliers, so 100Mi equals to 104857600 bytes.

See full usage by running trenn --help.

Requires GLib 2 (Debian package libglib2.0-dev) to build. The process of building is a normal CMake one:

mkdir build
cd build
cmake ..
make

These programs are free software: you can redistribute them and/or modify them under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Full license text