Hello,
I need some help regarding using DT with a NAS.
My pictures are stored in NAS and I would like share my productions with a workstation and a laptop where is DT is installed (on both).
Sometimes happens that I start production from the laptop and I finish with the workstation.
I read something about local copy, but I understood is relating removable storage, sometimes connected or not. In my case the NAS is always connected and available.
I read also regarding local DT library.
I’m little bit confused because I don’t understand how local library can be synchronised on both DT installation.
At the end my question: can I use DT in this way ?
If yes, how should be configured ?
Thanks in advance and I hope I was clear because my english … 
You can enable check for changed xmp files on startup so if you edit a file with first machine then run darktable on the second machine dt can check if xmps were updated and take over these edits.
This check is done at startup of darktable.
Syncing the databases might work if the file paths are exactly the same on both machines - but then you also can run darktable with a custom library path accessible on both machines…
Make a shared folder for your images on the NAS. Make sure that folder has the same driver letter on all PCs.
you also can run darktable with a custom library path accessible on both machines
Should be no problem to have that in the NAS folder too. But maybe it will have performance issues. If not, would be perfect.
@st.raw @MStraeten
Thank you for your help !
What I understood is that the pathname is stored in the library. But… I forgot to tell that the workstation is Win10 while the laptop is Linux.
I’m pretty sure someone will suggest me to switch the workstation to Linux 
.
It could be a solution also because the DT performances are better, but I can’t in this moment.
I’ll investigating about local copy if can help me.
A last ditch solution could be using the dt database only on one post, in combination with XMP sidecars.
On the other post, you then start dt with darktable --library :memory:. Disadvantage: you (may) have to re-import the images you want to wirk with each session.
Is it really necessary to have the same drive letter on all stations? One install of dt doesn’t know about the other, or how the file structure looks to the other… In any case, drive letters don’t exist under Linux…
One big problem might still exist, if you use LUTs, watermarks and such: afaik, the path to the external file used is stored in the xmp, not the file contents. Not sure how hard it is (or if it is even possible) to make sure those paths are the same for all posts.
Probably not. I have darktable on the external drive too, then it makes sense. With dt on the HDD most likely doesn’t matter.
I made some test in order to use ‘local copy’ feature (images copied from my NAS) for performance issue.
I state that the option ‘write sidecar for each …’ is disabled; sidecarfile will be saved manually, only for edited images (I prefer).
My intent is to work as a git: ‘DT local copy’ = Git Pull
- In that state I would like process the photo locally
- write the sidecar file locally
- ‘DT resync local copy’ = Git Push, in order to copy sidecar file to NAS
In this way I could edit the same picture from the workstation and the laptot (not at the same time) following the same flow.
But ‘write the sidecar’ always save on the drive mapped for accessing NAS, even if disconnected (with error).
It’s not all: in step 3) if I try to ‘resync local copy’ to the disconnected mapped drive, DT tells the the local copy is removed without save sidecar file.
By logic, I expected sidecar file to be copied locally, if the image is in ‘pull state’.
I think the same problem is there if using external memory.
Somebody could tells me if saving sidecar as I described is the right behaviour ?
It could be a bug that could be fixed in the next DT release (3.8 ?).
Thank you.
An alternative idea maybe, what about using Syncthing?
This could synchronise your photos and xmp files between your workstation, laptop and NAS.
So you work locally on your workstation, files get synched to your NAS and to your laptop. Yes, that means that your files exist in 3 fold (workstation, nas, laptop) and that you do need sufficient disk space and each device…
I’ve been through this process myself and I find this the most convenient.
But I only sync the last year to between my devices and not my entire photo library.
But nothing prevents you creating multiple tasks in syncthing to suit your needs.