My DB is in Archivelog mode on Oracle 8 (on win NT) and
I am getting below warning message frequently since last 7 days.


\orant\bin\oracle80.exe warning - The foolowing error occured during oracle redo log archival

Oracle Instance ORCL - Can not allocate log,archival required.
Press ENTER to acknowledge message


After pressing enter it will continue.

For which reason this warning messages and any solution for the same?