"No space left on device" Error

Getting this serious error, please advise, there is only one very simple field right now.

Warning: session_start() [function.session-start]: open(/tmp/sess_sqlaukggh0qfre4s0tnsme50a6, O_RDWR) failed: No space left on device (28) in /home/client/www.client.com/wp-content/plugins/custom-field-suite/includes/classes/form.php on line 30

my export:

<br />
<b>Warning</b>:  session_start() [<a href='function.session-start'>function.session-start</a>]: open(/tmp/sess_sqlaukggh0qfre4s0tnsme50a6, O_RDWR) failed: No space left on device (28) in <b>/home/client/www.client.com/wp-content/plugins/custom-field-suite/includes/classes/form.php</b> on line <b>30</b><br />
{"9":{"post_title":"Bike\/Frame Information","post_name":"bikeframe-information","cfs_fields":[{"id":"1","name":"bike_type","label":"Bike Type","type":"select","notes":"","parent_id":0,"weight":0,"options":{"choices":{"{empty}":"Select One","Cyclocross":"Cyclocross","Mountain":"Mountain","Road":"Road"},"multiple":"0","required":"0"}},{"id":"2","name":"bike_material","label":"Bike Material","type":"select","notes":"","parent_id":0,"weight":1,"options":{"choices":{"{empty}":"Select One","Steel":"Steel","Aluminum":"Aluminum","Titanium":"Titanium","Carbon Fiber":"Carbon Fiber"},"multiple":"0","required":"0"}}],"cfs_rules":{"post_types":{"operator":"==","values":["post"]}},"cfs_extras":{"hide_editor":"0"}}}<br />
<b>Warning</b>:  Unknown: open(/tmp/sess_sqlaukggh0qfre4s0tnsme50a6, O_RDWR) failed: No space left on device (28) in <b>Unknown</b> on line <b>0</b><br />
<br />
<b>Warning</b>:  Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in <b>Unknown</b> on line <b>0</b><br />

I disabled the plug in and everything is back to normal minus the extra fields… I might try a reinstall at some point.

https://www.ads-software.com/extend/plugins/custom-field-suite/