What device is used to prevent data loss in the event of power failure for a storage system?

A UPS, or Uninterruptible Power Supply, is designed to provide backup power to a storage system during a power failure. This ensures that the system can continue to operate for a limited time, allowing for safe shutdown procedures to be initiated or to keep critical systems running until the main power can be restored. The UPS acts as an intermediary power source that allows data integrity to be maintained, as it gives administrators the chance to save work and prevent data loss that could otherwise occur during unexpected outages.

While RAID controllers can help protect against data loss through redundancy, they do not provide any power backup capability. Similarly, batteries can be used in some systems as power storage, but they don't typically function as standalone devices for protecting a storage system. A Power Supply Unit (PSU) is essential for delivering power to the components of a server but does not offer power during an outage, highlighting the necessity of a UPS for uninterrupted operation and data integrity.