topic Re: Workspace or data source is read only in Python Questions

Workspace or data source is read only

MattEiben — Tue, 28 Oct 2014 23:09:17 GMT

Hello everyone,

I've been having a raster processing arcpy problem for a while and am hoping the Python community may have some insight.

This is part of a much larger and fairly complex script that is set up in a batch fashion. The script is designed to run through batches of hundreds of input points. The raster processes the tool is having problems on are usually one of the following:

arcpy.sa.ExtractByMask

arcpy.sa.ExtractValuesToPoints

arcpy.sa.Int

arcpy.sa.Combine

The error is as follows:

The problem is definitely not with the tool, as the error can happen on batch process 10 up to well over process 100, but this error inevitably comes up. From the error, is almost looks like ArcMap is writing some sort of temporary files to the local GDB before its saves the product to it's final location, but somehow locks itself out of its own process. Based on my experience so far, this seems to be a ESRI arcpy bug, but I was hoping maybe someone in the community has had and/or solved this problem before.

Thanks in advance for any insight!

Re: Workspace or data source is read only

curtvprice — Wed, 29 Oct 2014 06:48:40 GMT

Are you sure you're not running out of disk space?

For best results when doing raster processing, you should set these two environments to a writeable folder with lots of available space, to make sure there is plenty of room for temporary files.

arcpy.env.workspace

arcpy.env.scratchWorkspace

Re: Workspace or data source is read only

MattEiben — Wed, 29 Oct 2014 14:56:37 GMT

There is definitely plenty of disk space left. I originally thought it may be due to writing to a network, but (besides being a little faster), writing to the local machine produces the same error eventually. I did think of a workaround last night that may get by this, though not fix the problem.

Essentially, just wrap each the problem raster processes in some sort of try/expect loop that detects if an exception was thrown and tries the process again. A very hacky workaround, but may keep the batch from bombing out after 30+ minutes of processing.

Re: Workspace or data source is read only

DanPatterson_Retired — Wed, 29 Oct 2014 15:14:14 GMT

try saving it to a local drive that you have confirmed you have write permissions to. Also ensure the path has no spaces or other unsavory characters. Sometimes when stuff gets copied fro dvds network drives, write permissions are set