I think the best way for u is to Block the IPU end the file mountings and formatt by FICRI and dump on a clean disk twice will take longer though but its safe.
BR
ecptfa
BLEQI:EQU=1-0-XX-00;
IOSIE:NODE=SYSN,IODEV=SYSDISK1;
FIMOE:SUBFS=SYSSUBFS11;
FIMOE:SUBFS=SYSSUBFS21;
FICRI:SUBFS=SYSSUBFS11,SIZE=XX;
FICRI:SUBFS=SYSSUBFS21,SIZE=XX;
FIMOI:SUBFS=SYSSUBFS11;
FIMOI:SUBFS=SYSSUBFS21;
IOSII:NODE=SYSN,IODEV=SYSDISKX,SUBFS=SYSSUBFS11&SYSSUBFS21,SIPOS=X;
BLEQE:EQU=1-0-XX-00,ALLFM=YES;
You can use this procedure if u are using BC 9 its the same for BC 11 as well I guess but maybe something different for NIU. The X values u will have to check in ur systems.
You can use these cammands