The logged in user is a member of a group that has a write permission on a folder. But when this user is trying to write something, permission is denied.The log below summarizes the question:subv:/www/tracer/ whoamifranksubv:/www/tracer/subv:/www/tracer/ ls -ltr total 4drwxrwxr-x 2 root tracer 4096 Jan 20 12:25 convert.tracer.comsubv:/www/tracer/ groups frankfrank : frank tracersubv:/www/tracer/ > convert.tracer.com/test-bash: convert.tracer.com/test: Permission deniedsubv:/www/tracer/Output of ls -bail /www/tracer/convert.tracer.com/:subv:~/ ls -bail /www/tracer/convert.tracer.com/total 838010883 drwxrwxr-x 2 root tracer 4096 Jan 20 12:25 .38010882 drwxr-xr-x 3 root root    4096 Jan 20 12:25 ..subv:~/ 
Group member cannot write even with write permission
files;permissions;group
Group membership is re-read on login. groups seem to report the groups you are in according to /etc/group and does not reflect membership of groups in the current session.Use the command id -Gn to show the groups that you are currently an active member of. Solution: relogin to apply the group changes.