Data Management

Your data is sacred. Make copies. Never work on the original data; always work on a copy. Name files in ways that will make sense to you later. You should never trust one computer with your data, always back it up.

You need to know where to keep your files on lab computers and where you can keep your files safe when you aren’t working on them!

  • Safe to work on files, but NOT safe to keep them: Some places on the lab computers get erased every time you log in/out! This includes your Desktop, Documents, and Downloads, as well as the C:\temp\ folder. If you do put files in these locations, be sure to copy them to somewhere safe (see below) before you log out.
  • Safe to work on files, somewhat safe to keep them, but not private: Some places on the lab computers don’t get erased regularly, but they are not private and can be accessed by others. This includes the local D: drive. Anything you put there stays there and is accessible to anyone who logs in to that specific computer. Put your materials in a folder that you name after you.
  • Safe to keep files, safe to work on files, but not fast: Some places on the lab computers are actually not ‘local’, but are ‘on the network’ / server. This includes the H: drive. Files on the H: drive are only visible to you. They aren’t deleted until after the term is over. The disadvantages of the H: drive are that it is slow and that space is shared and limited. If your data is relatively small, you can work with it from the H: drive directly.
  • Safe to keep files, but NOT safe/practical to work on them: Some of you may elect to copy your files to/from cloud services, some of which may have their data centers outside of Canada. Some of you may elect to purchase USB keys/sticks that you copy your data to/from at the end/beginning of a work session.

Lab Data comes in .zip files, which you need to extract before you start working

  • You will download your lab instructions and materials from the course website in ‘.zip’ file format. (A zip file takes a number of different files and compresses them into a single file. This makes them a convenient way to transfer GIS projects among people.)
  • You have to unzip the zipped file before you can start working.
    • Use the File Explorer (?) to find the zip file.
    • Move the zip file to the location where you want to work on it (e.g., H:\).
    • Double click on the .zip file. You should be asked whether you want to use the default utility, PeaZip, if you are on a lab computer. Use PeaZip.
    • Once PeaZip is running and you are looking at the contents of the zip file, you click on the ‘Extract’ button, and select where you want the files to go. It’s recommended to give each new project its own new folder.
    • Once you’ve unzipped the files, you can find them in the File Explorer.

A day of working on a Geography Lab Computer:

  1. Get your files (from a .zip file, from the H: drive, from a USB stick, etc.) and put the files somewhere where you can do work (e.g., the D: drive, C:\temp\, or even just on H:; see above for more explanation).
  2. Do your lab. Save your work periodically.
  3. When you need to leave the lab:
    1. SAVE your work
    2. Close all programs (ArcGIS Pro, QGIS, etc.)
    3. If you wish, ZIP your directory/files by right clicking on your project’s folder and using Windows’ Send To … Compressed folder. This creates a new single .zip file with your work in it. Name it something different from the zip files we gave you: lab1-2023-01-20.zip, after the date, perhaps. The first time you try this, verify that you’ve gotten all the files into the zip file by unzipping it again, then attempt to load your work back into the program.
    4. Then, the key step. BEFORE you log out, copy your files to somewhere safe to store files. See the top of this page for more explanation. Candidate locations to store files include: your USB flash drive, the H:\ drive, or a cloud service you have.
    5. Double check to see all files have transferred.
    6. Log off – when you log off C:/temp, Desktop, Documents, etc., will be purged. You are responsible for your lab and lab data.
  4. To continue working on the lab, when you come back to the lab, bring anything you need (e.g., your USB flash drive, if you are keeping files on one). Open up wherever you stored the files, and repeat step 1 above.

Troubleshooting:

When I open my map I get red exclamation points next to my layers and nothing shows on the map. What do they mean? Do I have to do my lab all over again?

This is a problem often experienced when working with ArcMap (see below). However, it doesn’t seem to be as much of an issue with ArcGIS Pro. It appears as if ArcGIS Pro uses relative path names by default, so the dreaded red exclamation points are less likely to appear.  However, they do appear if the data (e.g., the geodatabase) isn’t where ArcGIS Pro expected it. If the issue does arise for you, you will need to click on Project, then on Options, and check out the path names under Current Settings.  You can then reset the path names–to point to where the data is being stored–if necessary.

Some GIS are picky about how the data is organized. It expects to find the layers, etc., in the same organizational structure (directories / files) as was present the last time you saved the document. If, after closing ArcMap, for example, you rename the folders or change the location of files, the program will expect to find the layers in the original location(s), but since the location (i.e., directory name(s)) has changed, ArcMap won’t be able to locate the data. Check with TAs or Jose about how to fix this error, assuming of course you have not deleted the files. (Hint: Check out ArcGIS Pro Etiquette and relative path names.)