OPEN dataset getting no authority dump

Using OPEN dataset getting no authority dump.

Statement used is

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OPEN DATASET y_filename FOR APPENDING IN TEXT MODE ENCODING DEFAULT

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This statement is giving dump message "no authority"

y_filename has the value /usr/sap/tmp/text03012008.txt

Above mentioned file "text03012008.txt" does not exit on Application server and should be created

kindly advsie