Error Logging In

I've been using aMember Pro for almost 2 months but I got the following message when I tried to login to the admin area now:

Warning: session_write_close(): write failed: No space left on device (28) in /home/jm2u/public_html/members/admin/login.inc.php on line 90

Warning: session_write_close(): Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in /home/jm2u/public_html/members/admin/login.inc.php on line 90

Warning: session_start(): Cannot send session cookie - headers already sent by (output started at /home/jm2u/public_html/members/admin/login.inc.php:90) in /home/jm2u/public_html/members/admin/login.inc.php on line 91

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/jm2u/public_html/members/admin/login.inc.php:90) in /home/jm2u/public_html/members/admin/login.inc.php on line 91

No space left on device
Do you really think it is aMember problem? Contact your hosting provider instead.

No space left on device (administrator login page)

I am receiving a similar message - did you ever fix this problem? What was the cause / solution?

The message I receive is shown on the login page - it has been working fine until now and I didn't make any changes to explain the problem:

Warning: session_start(): open(/tmp/sess_29f0913a33350675a47c72c8ff1dec26, O_RDWR) failed: No space left on device (28) in /home/dropshippeuk/public_html/amember/admin/login.inc.php on line 103

Warning: session_start(): Cannot send session cookie - headers already sent by (output started at /home/dropshippeuk/public_html/amember/admin/login.inc.php:103) in /home/dropshippeuk/public_html/amember/admin/login.inc.php on line 103

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/dropshippeuk/public_html/amember/admin/login.inc.php:103) in /home/dropshippeuk/public_html/amember/admin/login.inc.php on line 103

Any help welcomed - I have contacted our hosting company but it's not like we are running out of web space or anything?