== What CRtools is == '''CRtools''' is an utility to checkpoint/restore process tree. Unlike checkpointSee main article here [http:/restore implemented completely in kernel space,it tries to achieve the same target mostly in user space. === Agenda === # Basic design (checkpoint == proc + SEIZE, restore == syscalls + execve)# What's required from kernel == Basic design == === Checkpoint === The checkpoint procedure relies heavily on '''/proc''' file system (it's a general place where crtools takes all the information it needs)criu. This includes:* Files descriptors information (via '''/proc/$pid/fd''' and '''/proc/$pidorg/fdinfo''')* Pipes parameters* Memory maps (via '''/proc/$pid/maps''') Though not all parameters can be observed this way, say the current '''brk()''' value of a process is not exported at all.CR_tools]
