Permissions on mounted filesystems

[thewho?]

Hello,
HP-UX11.0, N4000, LVM
This maybe normal behavior but need to confirm.
Before I mount a filesystem, I create a directory to mount it, then I set the permissions to that directory to 777.
But when I mount the fs on that directory, the permissions change to 755, Is this normal?
I've tried changing my umask to 000, but the result is the same.
Thanks,
Luis

[A. Clay Stephenson]

Hi Luis:

You are confusing the permissions of the mountpoint with those of the mounted filesystem. You should probably not set the mountpoint permissions to 777 (that is generally not secure; 755 would be better and owned by root). Users do need to have r-x permissions on the mountpoint to be able to access the underlying filesystem. THe permissions that the process accessing the mounted filesystem is that of the top level directory in that filesystem. You change that permission AFTER the filesystem is mounted.

Clay

[Joseph C. Denman · Accepted solution]

This is correct behavior. This info is written to the filesystem. Once you filesystem is mounted, you can then change the perm/ownership.

Hope this helps.

...jcd...

[thewho?]

Clay,
Thanks for the prompt reply.
I suspected that was the case, I was going to give you the 10 points but my mouse scroll button acted up and change it to 7. Sorry.

[linuxfan]

Hi Luis,

This is the correct behaviour, You never want 777 on mountpoint directory, 755 is the safest method(owned by root ofcourse). After you mount the filesystem you can change the permissions/ownership etc, However if it is a NFS filesystem, the permissions will have to be changed on the server exporting the filesystem, unless you have given root access to the client machine then you can modify the permissions (from the client as well)

-HTH
I am RU