Hi all,

I am not sure if it's linux or windows (or both) but I am trying to understand why after every daylight time adjustment the modification times of my files are off by one hour between the 2 systems. I have windows client (Windows XP) and Linux server (Suse Prof. 9.x) which exports a backup fs via samba. I regularly perform rsync from the windows machine to the backup fs on the linux server. Nothing fancy - the windows machine just maps the samba exported fs and I use cygwin rsync to sync the files.

The time has just moved one hour back this weekend - the Windows machine corrected the time automatically. The linux server had to be manually adjusted. But why are the file modification times off by one hour? All the modification times are one hour older on the linux server. Why?

Could it be that when you create a file on a windows machine in summer it will actually create a file with modtime one hour back on the disk but reports it with DST adjustment? That's the only explanation I can think of.

Windows XP - NTFS fs

Linux 9.x Suse - ext3, reiserfs, time is kept in local time in RTC.

thanks

--pv

Hi pvlogin
windows xp uses the RTC in local time mode and manages the DST adjustment by setting the RTC to the new time.
you say "time is kept in local time in RTC" on the linux server, but are you sure you have adjusted the RTC to the new time and not the system clock only ? Because you must use the command 'hwclock --set --date=' and not 'date' under root login to set the RTC.
Please give precisions on how you manually adjusted the time on the linux server.

I modified the time via yast ->system ->date and time -> modify time. I am not sure which time this actually modifies (I'll check that later once I get to the machine again). But - I have looked around and it seems that my problem is in windows - depending on if the DST in windows is turned on or off windows reports different times -

http://www.codeproject.com/datetime/dstbugs.asp

--pv

Apparently YaST modify time only changes the system clock like the date command.
To change the RTC you must do it manually in a console under root login with
hwclock --set --date=

see 'man hwclock' for the date format

You can check if
hwclock --show (RTC time)
gives the same time as
date (system clock time)

you can also run
hwclock --systohc
to set the Hardware Clock to the current System Time
(as said in 'man hwclock')