Error converting ePubs in Dropbox

[kovidgoyal]

Originally Posted by PeterT

My approach with DropBox is while I *DO* have a copy of my library there, I use AllwaysSync to replicate to that folder from my actual library. Yes; it means I use double the space on my PC, but I also feel confident that there will be no issues with DropBox and Calibre "arguing". Syncs ONLY go from my actual library to my DropBox folder; not the other way.

That is a good way to use dropbox, though personally, I just remove the middleman and sync directly across the computers I want sharing my library. I use unison to do that. That is a little less safe, than your method, but it means you dont have to trust a cloud provider for availability.

[Deljah]

I am a bit unclear on these posts. Is the issue that the OP was trying to do a mass conversion with files while in dropbox, so that files were being accessed simultaneously for opposing purposes?

Or, is the issue just having the files in dropbox at all? I am running calibre portable on my PC. I have the entire calibre portable installation and library also in drop box. I thought this was a great way of backing up calibre (with all the plugins and preferences set) and the library. I only run calibre from this one pc, so I'm not syncing across computers. I don't share my library with anyone.

Please let me know your thoughts. I'm pretty new and want to avoid catastrophe with my library. Thanks!

[DoctorOhh]

Originally Posted by Deljah

I am a bit unclear on these posts. Is the issue that the OP was trying to do a mass conversion with files while in dropbox, so that files were being accessed simultaneously for opposing purposes?

Simultaneous access by opposing forces was the problem.

Originally Posted by Deljah

Or, is the issue just having the files in dropbox at all?

Files in dropbox is fine.

Originally Posted by Deljah

I am running calibre portable on my PC. I have the entire calibre portable installation and library also in drop box. I thought this was a great way of backing up calibre (with all the plugins and preferences set) and the library. I only run calibre from this one pc, so I'm not syncing across computers. I don't share my library with anyone.

You will be fine. I run it the exact same way using calibre portable. PeterT's method above is safer because occasionally even doing individual conversions dropbox gets in the way.

Originally Posted by Deljah

Please let me know your thoughts. I'm pretty new and want to avoid catastrophe with my library.

I primarily use dropbox to sync between work and home computers. Dropbox has saved me from myself many times, but then again any decent backup would do the same.

[kovidgoyal]

If you want to put your calibre library directly in dropbox, follow these precautions:

1) Do not run both calibre and dropbox simultaneously. This is to prevent them both accessing the same files simultaneously. Instead run dropbox before starting and after quitting calibre.

2) Always run dropbox and let it finish syncing every time you quit calibre. This is to ensure that you do not accidentally make conflicting changes to the same library on two different computers connected to the same dropbox account.

3) Keep a backup of your library so that if something does go wrong you wont loose too much.

4) Do not share the same library between windows and non-windows machines. This is because windows has much shorter maximum path length restrictions.

[HarryT]

Originally Posted by kovidgoyal

On windows file locking is done by the windows kernel for all files automatically. Not by programs. Therefore, neither dropbox nor calibre are handling file locking incorrectly, since neither of them do any file locking at all. You simply cannot have two programs simultaneously accessing the same set of files in both read and write modes. If you do that, things *will* break. Putting a calibre library in dropbox is a horrible hack. If you're careful, you can get away with it, but when things break, you have only yourself to blame.

When Calibre becomes "lock aware", to allow it to work multi-user on network shares, that will presumably also allow it to work correctly with Dropbox? I believe that's somewhere on your development roadmap, isn't it?

[DoctorOhh]

Originally Posted by HarryT

When Calibre becomes "lock aware", to allow it to work multi-user on network shares, that will presumably also allow it to work correctly with Dropbox? I believe that's somewhere on your development roadmap, isn't it?

You may be right.

I spoke wrong earlier, it isn't two programs accessing a book at once. It is Dropbox accessing a book then calibre attempting the write and unable to write because another program has locked the file. Calibre errors at this point because it is unable to write to the file.

Possibly if calibre did two retrys five seconds apart before throwing the error things would work themselves out. Especially since this conflict is so rare to begin with.

[kovidgoyal]

Originally Posted by HarryT

When Calibre becomes "lock aware", to allow it to work multi-user on network shares, that will presumably also allow it to work correctly with Dropbox? I believe that's somewhere on your development roadmap, isn't it?

No. The multi-user support will be via the calibre server.

[HarryT]

Originally Posted by kovidgoyal

No. The multi-user support will be via the calibre server.

OK, thanks.