Google Cloud connecting first time through ftp but in few seconds reverting to permission denied on write (the file is going blank on this case)

Question

I am connecting to my project files through FileZilla (hosted in Google Cloud). It was working fine until yesterday. Starting yesterday I am getting issues:

1. When I restart the compute engine FileZilla is working for fine few seconds. Then it reverts back to permission issue or showing Failed while saving files.
2. I checked with permissions and everything looks fine. My project files is inside var/www/html

Status: Connected to {cloud_ip_here}
Status: Starting download of /var/www/html/{app_name}/api/application/controllers/Test.php
Status: File transfer successful, transferred 1,920 bytes in 1 second
Status: Starting upload of C:\Users\{my_pc_name}\AppData\Local\Temp\fz3temp-2\Test.php
Command:    put "C:\Users\{my_pc_name}\AppData\Local\Temp\fz3temp-2\Test.php" "Test.php"
Error:  /var/www/html/{app_name}/api/application/controllers/Test.php: open for write: permission denied
Error:  File transfer failed

Answer 1

Permission denied errors occur when you don't have the required permissions to make changes to a file that you're trying to edit over FTP. You can follow the steps in link given below in order to rectify the issue,

fix-ftp-permission-errors-google-cloud

Answer 2

Weirdly, the issue was server ran out of space and that's the reason it was showing permission denied. It has nothing to do with permissions. To check space in ssh of Compute Engine instance go for "df" command.