I’ve verified with our engineering team that the Drobo Share and Drobo FS don’t have support for the archive bit but the 5N does. Here is our KB article regarding backup programs that will work with the Drobo FS:
Drobo NAS devices (and their competitors QNAP and Synology) don’t natively use NTFS. The filesystem is shared via “Samba” which is Windows-sharing software for Linux. I haven’t tried to set Archive bit over Samba, but it wouldn’t surprise me if that didn’t translate.
I use rsync and CrashPlan to back up my Windows computers. I use various other tools to back up other OS’s. In years past, I used Retrospect and briefly Windows Backup.
CrashPlan maintains a list of files which were already backed up, and their hash. If a file is already on the list, and its size and timestamp hasn’t changed, then it skips it. Otherwise, it backs up the file. Once in a while (I configured this for 28 days), it checks the hash of every file and compares with what’s in the backup archive. Retrospect looks for changes pretty much the same way as CrashPlan does. SuperDuper! copies entire disks. It checks every file, every time. That’s slow, but effective. Unison is a file synchronization tool, not really a backup program. It maintains a list of every file and its hash, and compares both sets of files against that list, then flags anything that changed and either copies it or prompts the user to make a decision. rsync is another file sync tool. It defaults to checking just filesize and timestamp (mtime), but can calculate file hash if you wish.
UNIX dump just copies everything that was created or modified (mtime) since the last backup. You can set a “nobackup” flag on files to exclude them from being backed up. tar is even more stupid than dump.
Windows Backup and PKZip are the only backup tool I can think of which rely on the Archive bit to know what to back up. I guess it works, and it might be a little better than checking merely the timestamp, but it’s still easily fooled – and in any case, that doesn’t know anything about what you actually have backed up. I consider Windows Backup too brittle and vulnerable to bit-rot to recommend.
have you had a look at the windows tool called Syncback?
theres a few versions of it around, one is free and others do a lot of things but ive bene using it with my drobo gen1 to gen2 mirrorring and its very very good. (syncback se)
have a look as it might be able to do what you’re after… just make sure you know how to use it before you set something up to play safe etc…