|Could the Super Bowl power outage cause data loss on SSDs?|
|Written by Kent Smith - senior director of marketing for LSI's Flash Components Division|
|Thursday, 14 March 2013|
Could the Super Bowl power outage cause data loss on SSDs?
By Kent Smith - senior director of marketing for LSI's Flash Components Division
Most people fully understand that electronics are useless without power, but what happens when devices lose power in the middle of operating? That answer is highly dependent on a number of variables including what type of electronic device is in question.
For solid state drives (SSDs) the answer depends on factors such as whether an uninterruptable power supply (UPS) is connected, what controller or flash processor is used, the design of the power circuit of the SSD, and the type of memory. If an SSD is in the middle of a write operation to the flash memory and power to the SSD is disconnected, many bad things could happen if the right safety measures are not in place. Many users do not think about all the non-user initiated operations the SSDs may be performing like background garbage collection that could be under way when the power fails. Without the correct protection, in most cases data will be corrupted.
According to the Nielsen company, 108.4 million viewers were tuned into the 2013 Super Bowl in New Orleans only to be shocked to witness the power go down for 34 minutes in the middle of the game. If power can be lost during such an incredibly high profile event such as this, it can happen just about anywhere.
Inside the New Orleans Superdome stadium operations and broadcast server rooms
Usually this is enough power to support uninterrupted system operations until power is restored, or at least until technicians can complete their current work and shut down safely. However there are many times when UPS systems are not deployed or fail to operate properly themselves. In those cases, the server will experience a power failure as abrupt as if someone had yanked the power cord from the wall socket.
The LSI® SandForce® Flash Storage Processors (FSPs) are at the heart of many popular SSDs sold today. The FSP connects the host computer with the flash memory to store user data in fast non-volatile memory. The SandForce FSPs are specifically engineered to operate in different environments, and the SF-2500/2600 FSPs are designed to provide the high level of data integrity required for enterprise applications. In the area of power failure protection, they include a combination of firmware (FW) and hardware circuitry that monitors the power coming into the SSD. In the event of a power failure or even a brown-out, the FSP is alerted to the situation and hold-up capacitors in the SSD provide the necessary power and time for the FSP to complete pending writes to the flash memory. This same circuit is also designed to prevent the risk of lower page corruption with Multi-level Cell (MLC) memory.
Watch out for SSD solutions that provide backup capacitors, but lack the necessary support circuitry and special FW to ensure the data is fully committed to the flash memory before the power runs out. Even if these other special circuits are present, only truly "enterprise" SSDs that are meticulously designed and tested to withstand power failures are up to the task of storing and protecting highly critical data.
In the control room and down on the field
The LSI SF-2100/2200 FSPs are purpose-built for these client environments and operate with the assumption that power could disappear at any point in time. They use special FW techniques so that even without a battery present, as is the case with desktop systems, they greatly limit the potential for data loss.
The naked facts