Error ORA-01948: identifier's name length (31) exceeds maximum (30) When dropping a disk from a ASM

Hi all,

Environment RAC 11G  with 2 nodes on Oracle linux

I added 3 new disks(to a new storage)  to my diskgroup DG_OCR_VOTE and now i want drop the 3 disks old (old storage) and i get the error ORA-01948. Can anybody help me where is the error on command ?

Adding 3 disks: Ok.

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SQL> alter diskgroup DG_OCR_VOTE add disk '/dev/oracleasm/disks/OCR_VOTE04','/dev/oracleasm/disks/OCR_VOTE05','/dev/oracleasm/disks/OCR_VOTE06' rebalance power 9;

Diskgroup altered.

Dropping 3 disks : Error

SQL> alter diskgroup DG_OCR_VOTE drop disk '/dev/oracleasm/disks/OCR_VOTE01','/dev/oracleasm/disks/OCR_VOTE02','/dev/oracleasm/disks/OCR_VOTE03' rebalance power 9;