Removing, installing or re-seating a hard disk drive in a Datacenter Scalable Server (DSS) 7500 chassis can result in physical nearby drives going offline or becoming foreign if excessive force is used.
Excessive force can flex the HDD backplane resulting in physical nearby drives becoming disconnected or losing connectivity.
Exercise caution when replacing a drive and be sure to not use excessive force when removing, installing or re-seating a HDD.
See the DSS 7500 Owner's Manual for step by step instructions for installing / removing HDDs.