Ghost file limit too low
Unmapping large files in a Chroniton while still holding file descriptors can cause the checkpoint to fail.
An affected dump log:
chrononaut@greenglade:/chronode/timestreams/jolly-truck-9237/moments/00000034/volatile/complete$ sudo cat dump.log
Warn (criu/arch/x86/crtools.c:138): Will restore 20807 with interrupted system call
Warn (criu/arch/x86/crtools.c:138): Will restore 20810 with interrupted system call
Warn (criu/arch/x86/crtools.c:138): Will restore 24181 with interrupted system call
Error (criu/files-reg.c:665): Can't dump ghost file /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21 of 1566440 size, increase limit
Error (criu/cr-dump.c:1218): Collect mappings (pid: 24182) failed with -1
Error (criu/cr-dump.c:1641): Dumping FAILED.
The CRIU wiki has more information about the mechanisms at play: https://criu.org/Invisible_files
Recent commits have enabled configuring this limit threshold for RPC mode invocations: https://github.com/checkpoint-restore/criu/commit/d1439a67468d86e73b5df275dd352258fd8d5187