What type of upgrade on a Dell EMC PowerScale cluster requires rebooting of all nodes...

In Dell EMC PowerScale clusters, upgrades can be performed using different methods, each with its own impact on cluster availability and performance.

Simultaneous Upgrade:

Definition:

A simultaneous upgrade involves rebooting all nodes in the cluster at the same time.

Characteristics:

The entire cluster is taken offline during the upgrade process.

Downtime is required, making it suitable for non-production environments or maintenance windows.

Why Other Options Are Incorrect:

Rolling Upgrade (Option B):

Nodes are upgraded one at a time, allowing the cluster to remain online.

Side-by-Side Upgrade (Option C):

Involves building a new cluster and migrating data; nodes are not rebooted simultaneously.

In-Place Upgrade (Option D):

Refers to upgrading software on the existing hardware but does not imply simultaneous reboots.

Dell PowerScale References:

Dell EMC PowerScale OneFS Upgrade Guide:

Chapter on Upgrade Methods:

Describes simultaneous upgrades and their impact on cluster availability.

Provides guidelines on when to choose this method.

Best Practices:

Schedule simultaneous upgrades during planned downtime.

Notify users of the expected service interruption.