GCMS stands for Global Case Management. It is basically what Canadian Immigration and Citizenship department of Canada is currently using the following computer systems for processing immigration / visa applications. You can a few details about what's happening with your application.
Apply online at https://atip-aiprp.apps.gc.ca/atip/welcome.do?lang=en - scroll to the very bottom. Check that you have read the Privacy Notice and click on Continue button.
If you are physically in Canada, you can obtain them for free under the Privacy Act.
If you are overseas, someone else (a Citizen, Permanent Resident, or someone physically present in Canada) will have to obtain them for you under the Access to Information Act. This can be a relative, friend or sponsor, or a commercial service. For this there is a $5 fee (more if you use a commercial service), and you will have to provide consent.
Average time you will get your GCMS notes: 30 days
What it should look like: http://www.gcmsnotes.com/Sample_GCMS_File.pdf
Sources: http://wikimmi.com/index.php?title=Ordering_FOSS_and_CAIPS_notes
