On Nov 02, 2008 17:00 +0800, David Levi Hevroni wrote:> I encounter the following problem when trying to compile a program on a
> lustre volume: when I do ?make?, the program compiles. But then, when I
> switch to another computer and run make again, I get the ?clock skew
> detected? warning, but only on the executable that was created with the
> first ?make?.
The timestamps in lustre are based on the client clock. That ensures
that when running programs like "make" that you don''t get
clock-skew
problems between the client and server.
> When I take a look at the timestamp of the file, I see a valid time on the
> first computer, and just the day on the second. does anyone have any idea
> why such thing might happen?
Can you check "ls -l --full-time {file}" on both clients? When just
the
day is shown from "ls -l" it usually means that the file was modified
so
long ago that the time is no longer relevant (depending on the output format
chosen for your locale).
> This happens when I use NTP daemon, and also when I am synchronizing the
> clocks by myself. Running ?date? on both computers gives the same time
> (maybe 1 second difference).
This is very odd.
> Can it be a problem with the server? Does the date on the lustre server has
> any importance in this matter?
The server time should NOT affect the timestamps on the files, but it
isn''t impossible that there is a bug in this area. There were a few
timestamp bugs fixed recently, for the cases where a file was renamed
after it was created incorrectly changing the timestamp.
Please also check the time on the servers (both MDS and OSTs).
Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.