Although SSD technology has plenty to offer, it is still susceptible to data corruption and loss caused by power anomalies. All Virtium StorFly® and TuffDrive® SSDs include vtGuard®, a proprietary firmware technology that detects power anomalies and provides data saving processes that mitigate data corruption during power loss.
Three kinds of data corruption are possible:
1. Power fail during a write, but before the SSD has acknowledged receipt of data.
2. Power fail after the SSD acknowledges that it has data but before data has been committed to NAND flash.
3. Power fail after the SSD has data in NAND but before it has been committed to the correct logical block address (LBA).
Here’s how Virtium’s vtGuard works with these data loss scenarios:
Each page in NAND has a journal. Data is written to a page and the write is complete only if the journal is updated successfully. No matter how much UPS you have, power fails during writing to a page in NAND are still possible.
Once vtGuard quickly detects a power failure, the SSD controller and firmware immediately cut off communication with the host, and a hold-up circuit kicks in. The hold-up circuit keeps enough voltage available for the data to be flushed from the internal RAM buffer to the active block.
On subsequent power-up the SSD scans for any data in the active block that has not been written to the proper user block. Any data found will be committed to the proper LBA and the active block will be recycled for new data. Virtium’s proprietary firmware contains a complex algorithm to evaluate the journal and determine which page is corrupted, which data is valid and to guarantee only valid data is returned.
Virtium’s industrial-grade components and solid, proprietary firmware with vtGuard ensure that data corruption from power outage is kept to an absolute minimum.