DST Clock Change System Backup PITA

[Dave-H]

Not sure where to put this as it isn't really OS specific, but I mainly use XP so that's why it's here!

We changed from UTC+1 to UTC last weekend here in the UK, and a recurring annoying problem which I always forget about cropped up.
I back up my system archive very regularly, and the source drive is FAT32 as I want to use it natively with Windows 98SE.
The destination backup drive is NTFS, as it has to be able to cope with files larger than 4GB, such as system image backups.
Of course every time the clocks change every single file has to be re-copied across because their time stamps have changed, which takes ages and is a real PITA.
I know why this happens, it's because FAT32 and NTFS handle timestamps differently, but is there any way around this?
Also I synchronise some of the archive to my netbook, which is all NTFS drives, using the Windows Offline Files system.
The same thing happens here, every file has to be copied, including unchanged ones that are several gigabytes, and it takes hours and hours!
Is there really no answer to this other than converting my archive drive to NTFS or just putting up with it twice a year?!

 

[jaclaz]

You could make a script to "touch" each and every file, or use "fixed" GMT time on all systems, or - and this greatly depends on the used backup software and on your actual requirements (please read as "requirements" and not as "fancies") allow a "wider" gap for synchronization: 
https://rsync.samba.org/daylight-savings.html

A number of backup softwares can understand the difference and act correctly, as an example, robocopy (since the Vista  version) has a /DST switch.

Please note how different Windows NT OS versions behave differently (the separating lne is between Vista  and 7):
https://winscp.net/eng/docs/timestamp

http://www.codeproject.com/Articles/1144/Beating-the-Daylight-Savings-Time-bug-and-getting

Yes, it is a mess.

jaclaz

 

[Dave-H]

Thanks jaclaz!
My backup software is QuickMirror, and I've now done what I should have done in the first place and checked its settings! 
Do you think the option I have highlighted here will fix the problem, and will it cause any others?!

It has always been set to the "date, time and size" default before, which has caused the issue of course!

This may well fix the backup problem, but I can't see any way of doing something similar with Windows Offline Files.
I've just finished re-synchronising the XP side of my netbook with the XP side of my main computer, and it took about ten hours as every file had to be replaced!

 

[jaclaz]

Yep, at first sight that new settings should skip files where size and contents (I presume that some form of hash is performed and checked )  have not changed.

I have NO idea what "Windows Offline Files" is, let alone how it works (or completely fails to work ), isn't it a Windows 7 (and I presume later) "feature" only?

https://helgeklein.com/blog/2012/04/windows-7-offline-files-survival-guide/

jaclaz
 

[Dave-H]

Thanks again, I'll change the QuickMirror settings and hopefully I then won't have to re-copy the entire contents of my archive drive twice a year!
I just needed reassurance that changing that setting wouldn't have any obvious other disadvantages.

Windows Offline Files is there in Windows XP (but only the Professional version I think, not the Home version).
It's a way of keeping selected files on one computer synchronised with files on another computer, mainly useful to synchronise files between a portable computer and a fixed desktop, at least that what I use it for! It means I can have a lot of my archive files with me when I go away with my netbook, and I just re-sync before I go away to make sure it's up to date with what's on the desktop. I very rarely if ever make changes to the files on the netbook while I'm away, but if I did those changes should carry back over to the versions on the desktop the next time I sync.

Unfortunately it obviously gets thrown when the clocks change as one of the drives it's synchronising is a FAT32 drive and the other is NTFS.
It wouldn't be an issue except that it takes so long to re-synchronise everything, even with the two computers directly connected together with an Ethernet cable!

 

[Dave-H]

Sadly it looks as if using that option on QuickMirror will not solve the problem.
With it or any of its variants set, it checks every file really slowly every time I run the mirror, even though the log says it hasn't changed any of them!
This is taking nearly as long as actually copying them would, and it's doing it every single time too, not just twice a year!
I can only assume this is because it's checking the content of all the files every time, which is always going to be really slow.
Unless there is any other workaround, I guess I'm just going to have to accept that it will have to do a full copy twice a year after the clocks change.

 

Edited November 6, 2016 by Dave-H

[pointertovoid]

For folder synchronization and for backups, I use Free Commander
www.freecommander.com
which offers the options "ignore 1h difference" and "ignore 2s difference" and even "ignore the date" when comparing two folders before making the needed copies.

I haven't noted down which version works on W98se, but 2009.02 runs very well on W95b.
2009.02b would be officially the last on W2k but as it looks, the author maintains a broader compatibility than what he guarantees, so you may try a more recent one on W98se too.

More generally, I strongly recommend this nice piece of software, with which I have never made a mistake.

Edited November 13, 2016 by pointertovoid

[Dave-H]

Not a gratuitous bump, although I've just had to completely re-backup all my files again today as the clocks changed, which is what's made me think of this.

As well as the already documented here issue of backing up a FAT32 drive to an NTFS drive, I've also noticed another strange thing that I've now confirmed happens when the clocks change.

I have a lot of my archive drive folders set to "thumbnail" view mode, for images and video files, and every time the clocks change, all of the thumbnails seem to have to be re-created. Why would that be? This is completely on a FAT32 drive, no NTFS issues. Surely if all the files on the drive have their timestamps changed when the computer clock moves forwards or backwards an hour, by the same amount, why should that cause the thumbnails (stored in the thumbs.db files) to have to all be regenerated?