Access to server filesystem is not required. You can get logs using these steps:
You can follow these steps to configure logs:
On JIRA/Confluence, go to System -> Logging and Profiling.
Click on Configure in Default Loggers section.
Enter com.miniorange.sso.saml in package field and select Debug in logging level. Click on add.
After these steps, perform single sign-on again. This time logs will be recorded. Then Download Support zip using these steps:
Go to System -> Troubleshooting and support tools.
Proceed to create support zip.
Keep only Jira Application Logs option selected.
Click on Create zip and then Download zip.