could not write to the log file

1566605221 100.24.209.47 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 100.24.209.47 0 rows affected
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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