Hello !
Does that mean that the sess_ in /tmp/ cannot be made ?
No.
The mx 2.1 stores the session-data in the database not in /tmp
You need a database-table named {prefix}_sys_session in your database.
If needed here is a dump of the database strukture.
You have to set the {prefix} to your database prefix ....
#
# Tabellenstruktur für Tabelle `nuke_sys_session`
#
CREATE TABLE `{prefix}_sys_session` (
`sesskey` varchar(32) NOT NULL default '',
`expiry` int(11) unsigned NOT NULL default '0',
`data` text NOT NULL,
PRIMARY KEY (`sesskey`)
) TYPE=MyISAM;
greeting
jubilee