Dell PowerFlex 4.5.x Administration Guide

Overview of running scripts on hosts

PowerFlex can be used to run user-provided scripts on nodes hosting MDM or SDS components. This feature is supported on Linux-based (bare-metal or virtual) nodes only.

The PowerFlex Installer can be used to run a user-provided script on a node where PowerFlex is deployed. This feature can be used for any purpose external to the PowerFlex system, such as running a set of CLI commands, patching an operating system, and more. The feature allows the running of scripts in a safe manner, both from a security and a data integrity perspective.

PowerFlex Installer orchestrates the running of the script, ensuring that SDSs are placed in Maintenance Mode, to protect data during the process. In addition, parallel execution of scripts is only permitted on SDSs located in different Protection Domains. After the scripts have been run on an SDS, it exits Maintenance Mode.

Optionally, servers can be set to reboot after execution of the script. The process can also run a verification script either after the reboot, or after execution of the script, when no reboot is required.

The execution phase of this feature can be summarized as follows:

1. The system validates the following:
   • The patching script exists on the node after it was uploaded from the PowerFlex Gateway
   • No failed capacity exists
   • Sufficient spare capacity exists
   • The MDM cluster is in a valid state
2. Run the script on one host, using the following priorities:
   1. SDS only hosts, each time on a single SDS, unless the option In parallel on different Protection Domains is enabled
   2. Tiebreaker
   3. MDMs
      NOTE:The script will not run on a primary MDM. A switch-over MDM command will be run prior to running the script on a primary MDM. The script will not be run in parallel on multiple MDMs or tiebreakers.
3. SDS enters Maintenance Mode.
4. The script runs on the host.
5. The host reboots (if configured to do so).
6. The validation script runs on the node (if configured to do so).
7. SDS exits Maintenance Mode.