Negative value for undo tbs usage

[Tassleh0ff]

Hi, I have a problem with an old Oracle 9i instance which returns negative values for undo tablespace usage.

for example we have an undo tbs (UNDOTBS2) made by 3 10.000MB datafiles. With an 80% warning threshold and 90% critical threshold this is the result: [DBMS] [nrpe@oracle ~]$. /etc/sysconfig/nrpe; /usr/local/nagios/libexec/check_oracle_health --connect ORATEST --method sqlplus --user nagios --password changeit --mode tablespace-usage --name 'UNDOTBS2' --warning 80 --critical 90 --units=% CRITICAL - tbs UNDOTBS2 usage is -0.56% | 'tbs_undotbs2_usage_pct'=-0.56%;80;90 'tbs_undotbs2_usage'=-168MB;24000;27000;0;30000 'tbs_undotbs2_alloc'=30000MB;;;0;30000

Does anyone have ideas on how to solve this? I also tried to check with different units (MB,GB) but the result was the same, same also with tablespace-free mode.

Thanks for any info or hint.