It's expected that untar will preserve the stats of a file (for example, mtime), but in MooseFS, the mtime of files from untar are not preserved.
-rw-r--r-- 1 ubuntu ubuntu 997 Apr 19 16:07 README.txt
-rw-r--r-- 1 ubuntu ubuntu 997 Apr 25 06:07 README.txt
openat(AT_FDCWD, "profiles/README.txt", O_WRONLY|O_CREAT|O_EXCL|O_NOCTTY|O_NONBLOCK|O_CLOEXEC, 0644) = 4
write(4, "Installation profiles define add"..., 997) = 997
fstat(4, {st_mode=S_IFREG|0644, st_size=997, ...}) = 0
utimensat(4, NULL, [{1493100371, 505698059}, {1492618042, 0}], 0) = 0
close(4) = 0