could not write to the log file

1566605221 SQL: CREATE TABLE IF NOT EXISTS Tbl_Status ( StatusId INT(11) NOT NULL AUTO_INCREMENT, BatteryId INT(11) NULL DEFAULT 0, LkupTestId INT(11) NULL DEFAULT 0, users_id INT(11) NULL DEFAULT 0, StatusStatus VARCHAR(50) NULL DEFAULT '', FlashScore FLOAT(6,3) NULL DEFAULT '', AccuracyPercent FLOAT(5,2) NULL DEFAULT '', MeanReactionTime FLOAT(6,3) NULL DEFAULT '', SDReactionTime FLOAT(6,3) NULL DEFAULT '', PRIMARY KEY (StatusId), UNIQUE (users_id, BatteryId, LkupTestId) );
>1566605221 0 rows affected
Warning: Unknown: open(/var/lib/php/session/sess_8kq86gb3rpc3k40f74mgs8hen5, O_RDWR) failed: No space left on device (28) in Unknown on line 0

Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/lib/php/session) in Unknown on line 0