SQL> alter database datafile '+DG2/klrqrac/datafile/gasdata05.263.764259791' resize 26961M;
alter database datafile '+DG2/klrqrac/datafile/gasdata05.263.764259791' resize 26961M
*
ERROR at line 1:
ORA-01237: cannot extend datafile 11
ORA-01110: data file 11: '+DG2/klrqrac/datafile/gasdata05.263.764259791'
ORA-17505: ksfdrsz:1 Failed to resize file to size 3451008 blocks
ORA-15130: diskgroup "DG2" is being dismounted
ORA-15066: offlining disk "DG2_0001" may result in a data loss