The criu utility dumps the state of processes/containers into a set of image files. This article describes the format of them.
General format description ==
Most of the crtools image files begin with 32-bit magic cookie followed by zero or more entries of the same type (not size!) . Most of the entries are encoded in the Google Protocol Buffers format and each is preceded with 32-bit entry size value (not including this 32-bit value itself). Optionally each entry may be followed by extra payload which depends on the entry type.
IOW image files look like
The amount of entries in a image file depends on the type of file.
== Types of image files ==
Images encoded with ProtocolBuffers can be one of
; Array image files
There are , however, images which are not in ProtocolBuffers.
; Memory dumps