The pureinstall command is a low-level Purity operating system utility used strictly by Implementation Engineers and Pure Storage Support to install or upgrade the Purity//FA image on a controller's boot drive before the array is logically initialized.
When an Implementation Engineer unpacks a new FlashArray, the controllers may ship with a factory default version of Purity. If the customer's deployment requires a specific target version of Purity//FA (e.g., to match a fleet standard or enable a new feature), the engineer must boot into the controller via the local KVM/Serial connection and log in as the puresetup user. From here, they mount a USB drive containing the .ppkg firmware file and execute pureinstall purity- < version > .ppkg.
This process writes the new Purity operating system to the alternate boot partition. After executing pureinstall and rebooting the controller to boot from the new partition, the engineer then runs the puresetup newarray command (or puresetup secondary on the peer controller) to logically initialize the array, assign management IP addresses, and set the array name. Therefore, pureinstall must always be run prior to initialization.