you can't at the memoent. if you intention is to move the ide drives out of the way, then DiskIdxMap boot paramenter will help, excerpt from source code comment /** * Modify disk name sequence. Each two characters define the start disk * index of the sata host. This argument is a hex string. * * Detail information: * http://synowiki.synology.com/MediaWiki/ ... _DiskIdMap * * For example, use DiskIdxMap=030600 will get the following result. * Disks of the 1st host: sdd, s