FAQ

Facing the “Too many open files” error

iota2 may open a lot of files at the same time to complete a run. With some distribution configuration, the error Too many open files the solution is to increase the number of files that can be opened at the same time thanks to the command :

ulimit -u #inform you about the current limit (ie : 4096)
ulimit -u 5000 # increase user limit to 5000

More information at : https://linuxhint.com/permanently_set_ulimit_value/

Note

If your are using Sentinel-1 data, you have to fill the parameter srtm which is the path that contains DEM files. If you are facing the Too many open files, try to reduce the content of this directory as much as possible.

Facing the “PermissionError: [Errno 13] Permission denied: ‘/tmp/dask-worker-space/’” error

iota2 uses dask to schedule tasks. Dask needs to write temporary files at runtime. For some reason, dask may try to write files where it cannot, leading to a ‘Permission denied’ error. The solution is to tell dask where to put these temporary files by adding the line temporary-directory: /directory/path/to/store/temporary_dask_files to the file $HOME/.config/dask/dask.yaml.

Warning about parameters when the chain start

These warnings implies that the parameter is detected but not known by iota2. If you are not using a particular branch, ensure that your parameters are correct by looking at the corresponding builder:

If all parameters seem correct, that probably means that you are not using the latest iota2 version. Ensure that the .condarc file is correctly filled, and try to re-install iota2. In last case, open a issue with the chain version, the .condarc contents and the warning message.

is iota2 able to mix sensors ?

In the general case, no. Except in the case of Sentinel-2 and Sentinel-1 where the Sentinel-1 data has been tiled with iota2.

Possible workaround : The images from the various sensors must first be processed by the user so that all the data can be superimposed (same origins, x/y sizes, spatial resolution).