Strange Error in Trace File

I'm getting the following error in an Oracle 6.0.36 RDBMS trace file. We are running in NOARCHIVELOG mode. What does ``cannot allocate new log'' mean? Why does it``need checkpointing''? I have referred to the RDBMS Guide but with no success. And if there were an error message _number_ I could look it up.

Note that we have three log files and that the error cycles between each of the three.

    $ tail 3_10070.trc

    Advanced to log sequence 670 file /u1/hb/dbs/log1hb.dbf     Advanced to log sequence 671 file /u1/hb/dbs/log2hb.dbf     Tue Nov 1 23:50:43 1994
    cannot allocate new log, seq 672, needs checkpointing     Advanced to log sequence 672 file /u1/hb/dbs/log3hb.dbf     Advanced to log sequence 673 file /u1/hb/dbs/log1hb.dbf     Tue Nov 1 23:52:19 1994
    cannot allocate new log, seq 674, needs checkpointing     Advanced to log sequence 674 file /u1/hb/dbs/log2hb.dbf     Advanced to log sequence 675 file /u1/hb/dbs/log3hb.dbf

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Paul Beardsell                          SAM Business Systems Ltd
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