VirtFS - Jailshell - Trying to understand

[fcbinfo]

Hi.

The VirtFS and Jailshell, this works only for the users who have shell access?
If I don't have accounts with shell access, these 2 ones can be disabled or they are a part of security on cPanel?

I see that have docs on cPanel website, but no time to read all.

Thanks.

 

[Sys Admin]

if you don't need it you can just disable it.

VirtFS provides a jailed shell environment for a user who is connected to a server via SSH.

VirtFS (Jailed Shell)

 

[fcbinfo]

There something wrong then.

I don't have any accounts with shell access, and so many process inside this VirtFS.

When I go to reboot the server, sometimes I need to do manual restart on that, because the reboot command can't umount the VirtFS.

 

[cPanelMichael]

Hello

Please note that it's never a good idea to remove the virtfs directory or any subdirectories beneath it without understanding the implications of such an action. You can get a better understanding of how this directory operates at:

cPanel - VirtFS

In particular, this entry applies to your question:

As of cPanel & WHM Version 11.38, when a user's shell is configured to jailshell or noshell, Exim will run any process created from alias or filter files inside of VirtFS. Before version 11.38, these processes ran within the system.

Thank you.

 

[fcbinfo]

It's a new cPanel install, and when it's install, comes with version 11.40

The problem is only when restarting the server.
If you go on the WHM, and graceful restart, after some time, you see that server do not come back, and when we go to the real server console, have a message like this:

"Can't unmount the VirtFS"

If you don't do ctrl + alt + del on the server, this will stay on this screen for a life!

 

[cPanelMichael]

Have you reviewed the steps listed in document I referenced in my last response? In particular, review the sections on "Unmount the bind mounts" and "Clear orphaned bind mounts". Let us know if those instructions help.

Thank you.