## ISSU with SME Disk

In-Service Software Upgrade (ISSU) has the following requirements:

• No SME configuration changes must be in progress or initiated while an ISSU is in progress.

• Ensure that no data preparation operations are underway before you schedule ISSU.

• ISSU causes the crypto nodes (DPP) to become offline during the firmware upgrade causing host I/O traffic to be disrupted.

• The IT-nexus that are bound to that crypto node can end up migrating to a different crypto which can cause an imbalanced load distribution.

Note For SME disk, the ISSU from Cisco NX-OS Release prior to 5.2(1) is not supported and the SME Disk configuration will be rejected.

When upgrading from Release 5.2.1 to Release 5.2.6, the clusters have to be in the nonsignature mode and when downgrading from Release 5.2.6 to Release 5.2.1, signature clusters have to be deleted.