2012/10/5 bkabrda (Bohuslav Kabrda) <bkabrda / redhat.com>:

> I'm having a problem with File.utime on RHEL 5/CentOS 5. The File.utime m=
ethod seems not to set nanoseconds properly, see the attached test case, th=
at fails (the nanoseconds get rounded to thousand, so in fact I get microse=
conds). The test doesn't seem to fail on newer platforms with the same Ruby=
 version, though (RHEL 6/CentOS 6, Fedora 17). Note, that when creating/mod=
ifying files, the nanoseconds get set and are returned properly, so it seem=
s that they are supported by filesystem.

utimensat system call is required to set nanosecond filestamp.
It is available since Linux 2.6.22.
(glibc support is also required but I'm not sure the exact version.)

I guess RHEL 5/CentOS 5 is older than that.
--=20
Tanaka Akira