The FlashArray//XL chassis is engineered for high availability and is equipped with four Power Supply Units (PSUs). These are configured in a 2+2 redundancy scheme. This configuration means that the array requires two PSUs for normal operation, while the other two provide full redundancy. The system can sustain the failure of up to two PSUs without any operational impact, ensuring continuous availability of the storage array. This N+N redundancy model provides a higher level of protection compared to N+1 models.

A. 1+1: This describes a system with two total PSUs, where one is redundant. The FlashArray//XL has four PSUs.

C. 3+1: This describes a system with four total PSUs, where only one is redundant. The FlashArray//XL's 2+2 model provides redundancy for two PSU failures.

1. Pure Storage, Inc. (2022). FlashArray//XL Installation and Upgrade Guide. Document PURE-FA-XL-INSTALL-REV-A. Page 10, Table "Chassis Specifications", Row "Power Supplies". The document states: "Four 2200W power supplies, 2+2 redundant".

2. Pure Storage, Inc. (2023). FlashArray Hardware Guide. Section: "FlashArray//XL Chassis Specifications". The specifications table explicitly lists "Power Supplies: Four 2200W PSUs (2+2 redundant)".