waxweb Posted August 24, 2002 Report Share Posted August 24, 2002 hi, I have a problem with Mac Retrospect 4.3, and PC clients. At daylight savings, the PC clients require all their files to be re-backed up. This is not a problem with the Macs on the network. Unfortunately, the note in tech support does not cover this problem... only talks about Mac clients at dstime. How can I fix this? I thought to change to the PC version, but on testing it seems that the networking in the $89 pc version isn't as robust as in the mac version... even though I have a switch, multicasting doesn't work, and only the $600 version would let me specify a specific local IP number. thanks, David Link to comment Share on other sites More sharing options...
AmyJ Posted August 26, 2002 Report Share Posted August 26, 2002 Retrospect uses several matching criteria to find new or changed files. If one of the criteria has been changed, Retrospect will back up the file again. On Windows, Retrospect looks at creation date and time, modified date and time, size and name. If match only in same location option is set, Retrospect matches on the path, volume name and drive letter also. Retrospect has no way of changing these dates/times - it is done by the operating system or another program. Something as simple as changing the clock time on your computer by an hour _may_ change file dates and times. The end result is that the files have changed, so Retrospect backs them up again. The method you are using to change the time may be affecting the file criteria. Try setting the PC's to automatically adjust themselves for DST. The following Microsoft Knowledgebase article may shed more light on the issue you are experiencing: support.microsoft.com/default.aspx?scid=KB;EN-US;Q129574& Link to comment Share on other sites More sharing options...
waxweb Posted August 26, 2002 Author Report Share Posted August 26, 2002 hi Amy, unfortunately, that MS Article says: "When Windows NT automatically adjusts for daylight savings time, the times on files on Windows NT file system (NTFS) partitions and the events in the event logs are retroactively shifted by one hour, even though the files and event records were created before the daylight savings time change. " meaning Win2K as well... the only offered option is to Turn OFF [not on] the automatic daylight savings compensation, which is a bit silly. Since both NT OS's and HFS+ work the same way [store modification dates in GMT and make a conversion "on the fly" to the particular time zone setting], why can Retrospect handle this Mac/HFS+ <-> Mac/HFS+, but not Mac/HFS+ <->PC/NT ? Just to remind you, I run Retrospect on the Mac, and backup PC clients. Incidentally, this is not a problem with Win98, just NT/2K. If you suspect this might be my error, could you check where I could look, in case I haven't already? thanks, David Link to comment Share on other sites More sharing options...
AmyJ Posted August 26, 2002 Report Share Posted August 26, 2002 Retrospect can only determine that a file has, in fact, changed. There is no way for the program to determine _why_ the file has changed. Retrospect is not making the time changes - your Operating System is making the time changes. Retrospect is behaving correctly and backing up the file again. Link to comment Share on other sites More sharing options...
waxweb Posted August 26, 2002 Author Report Share Posted August 26, 2002 um... I didn't say or suspect that Retrospect was changing the file dates I did ask why this is fixed on HFS+, and not on NT? In the hope that you could mention a workaround, or offer any sort of hint. Since Retrospect, umm, Does Know Why in the case of HFS+.... or just to be clear, Retrospect is behaving correctly and NOT backing up the file again in the case of Mac <-> Mac backup. David Link to comment Share on other sites More sharing options...
AmyJ Posted August 27, 2002 Report Share Posted August 27, 2002 Retrospect gets all file information from the Operating System - names, dates, times, etc. If the system says the file is different, then it will be backed up again. Why are the files not getting backed up again on the Macintosh? Because the Operating System _is not_ changing the file dates/times, so the files exactly match what is in the backup already. Why are the files getting backed up again on the Windows clients? Because the Operating System _is_ changing the file dates/times for the reasons stated by Microsoft in their Knowledgebase article. Workarounds would include changing the time manually, or using these opportunities for recycle backups. Link to comment Share on other sites More sharing options...
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