[ome-users] Question about archiving OMERO files

[Robbert vd Zon]

Hi All,

I am new to the user group and am developing an archive solution for 
OMERO together with Perkin Elmer.

I saw that Bram Gerritsen had recently came across a problem of OMERO 
creating a black
image file when a user tries to access an image from which the file does 
not exists anymore (because
it is archived). I am having the same problem when developing our 
archive system.

When a project is archived, we copy all files that belong to this 
project to an archive location.
After that, we can 'purge' this project, which means that we remove the 
files from the data location.
When we need to restore a project it can happen that some (or all) image 
files already exists in the
data location. This can either be because the files are recreated with 
real data. If that is the case, we should
NOT override these files.
However, when these files were black images that were created on the fly 
because users were opening the
project while the files were archive, we would need to overwrite the 
files with the original ones.

I am searching for a way to know if a file is a black image created on 
the fly, or a real image with correct data.
Does anybody know if there is a way of finding that out?

Can I find this information in the database? I could check the events or 
compare the file-timestamp with something in the database.
Or is there a way that I can recognize it from the file itself (by its 
size or the content)?

We are trying to create a solution which works both with OMERO 3 and 
OMERO 4 without modifying OMERO.
So modifying the source is something we would rather not do.

Any help is highly appreciated

Thanks,

Robbert vd Zon
DAX Archiving Solutions