From time to time it is necessary to upgrade the microcode of your IBM Storage (ECKD/SCSI disk or tape).

For ECKD storage I recommend to shutdown the z/VSE system before you upgrade the microcode.

For Fibre-Channel-attached SCSI disks concurrent microcode upgrade is not supported.

z/VSE with the latest service level supports concurrent microcode upgrade for IBM tape storage. Please consult your device documentation for details. We recommend to take the tape units offline (z/VSE OFFLINE command) prior to the microcode upgrade or use the next maintenance window. Once the upgrade completed, take the tape units online again (z/VSE ONLINE command). Please check with your software vendors (e.g. tape management systems), if they support concurrent microcode upgrade.