MobileRead Forums - View Single Post - calibre library/ dropbox / system image questions

cybmole · 09-12-2014, 03:04 AM

any such test would take several hours.
i do have
1. a spare PC that has only a win 7 install + some utilities, thus only about 20Gb used.
2. a spare dropbox account
I'd need to activate & populate that drop box account on that PC, image the drive via usb to external portable , then make some changes to that dropbox, then restore the drive & inspect the results.

a shorter, less conclusive test would be:
1. set up and populate that spare dropbox account on that PC as before.
2 Now, just copy the dropbox folder AND all the dropbox app data,
3 make some dropbox changes,
4 take that pc offline, restore all the copied files, put it back online, observe the results.

That would only take an hour, including retrieving that pc from the attic. I guess I'm suprised that neither test has not already been done & documented, not anywhere that I can find anyway.

I think it likely that dropbox "secret" rules work like this.
in the dropbox cloud are files plus records of which PC uploaded each file
when dropbox sees that a local file ON THE PC THAT UPLOADED IT is different to the cloud copy, then it always uploads, ( i.e. there is no datestamp check ) but when it sees that a local file on some different PC is different to the cloud copy ( AND maybe also fails a date check) then it downloads. The effects on a calibre library would be subtle, if a book is simply tweaked or edited, no file names change, i'ts just that the content of the epub files changes & presumably the timestamp. So a test for how that is treated would involve changing the content but not the name of one or more dropbox files, in the above tests

FYI I went away & read up on how google drive works - the google drive files are NOT stored locally & take up no local space ( which was news to me) your local "google drive" is just a set of pointers to cloud files.. So google drive could still get confused or corrupted by system image restore, maybe ( I need to logic it out ) , but it would not be directly comparable to the dropbox case. I have not tried operating google drive across 2 PCs.

09-12-2014, 03:04 AM	#17
cybmole Wizard Posts: 3,720 Karma: 1759970 Join Date: Sep 2010 Device: none	any such test would take several hours. i do have 1. a spare PC that has only a win 7 install + some utilities, thus only about 20Gb used. 2. a spare dropbox account I'd need to activate & populate that drop box account on that PC, image the drive via usb to external portable , then make some changes to that dropbox, then restore the drive & inspect the results. a shorter, less conclusive test would be: 1. set up and populate that spare dropbox account on that PC as before. 2 Now, just copy the dropbox folder AND all the dropbox app data, 3 make some dropbox changes, 4 take that pc offline, restore all the copied files, put it back online, observe the results. That would only take an hour, including retrieving that pc from the attic. I guess I'm suprised that neither test has not already been done & documented, not anywhere that I can find anyway. I think it likely that dropbox "secret" rules work like this. in the dropbox cloud are files plus records of which PC uploaded each file when dropbox sees that a local file ON THE PC THAT UPLOADED IT is different to the cloud copy, then it always uploads, ( i.e. there is no datestamp check ) but when it sees that a local file on some different PC is different to the cloud copy ( AND maybe also fails a date check) then it downloads. The effects on a calibre library would be subtle, if a book is simply tweaked or edited, no file names change, i'ts just that the content of the epub files changes & presumably the timestamp. So a test for how that is treated would involve changing the content but not the name of one or more dropbox files, in the above tests FYI I went away & read up on how google drive works - the google drive files are NOT stored locally & take up no local space ( which was news to me) your local "google drive" is just a set of pointers to cloud files.. So google drive could still get confused or corrupted by system image restore, maybe ( I need to logic it out ) , but it would not be directly comparable to the dropbox case. I have not tried operating google drive across 2 PCs. Last edited by cybmole; 09-12-2014 at 03:23 AM.