URGENT: Out of disk space pg_xlog

I created a 10GB partition for pg_xlog and ran out of disk space today
during a long running update. My checkpoint_segments is set to 12, but
there are 622 files in pg_xlog. What size should the pg_xlog partition
be?

Postmaster is currently not starting up (critical for my organization)
and reports "FATAL: The database system is starting up" .

The log reports:
2006-12-22 10:50:09 LOG: checkpoint record is at 2E/87A323C8
2006-12-22 10:50:09 LOG: redo record is at 2E/8729A6E8; undo record is
at 0/0; shutdown FALSE
2006-12-22 10:50:09 LOG: next transaction ID: 0/25144015; next OID:
140986
2006-12-22 10:50:09 LOG: next MultiXactId: 12149; next MultiXactOffset:
24306
2006-12-22 10:50:09 LOG: database system was not properly shut down;
automatic recovery in progress
2006-12-22 10:50:09 LOG: redo starts at 2E/8729A6E8

This has been running for 20 minutes. What can I do? Please help!