CEO Talk with Smart Storage
August 1, 2012, Newark, CA—We talked with John Scaramuzzo from Smart Storage Systems. This is a spin out from the Smart Modular company and is focused on the use of MLC NAND flash in enterprise-level SSDs.
The change from Smart Modular, which is now focused on memory arrays based on DRAM and embedded memories, to Smart Storage Systems has been in the works for a while. The differing needs of the two sectors causes challenges in marketing and in the distribution channels. Now, the two groups are independent from each other. The changes in businesses is due to the changes in technology.
Smart Storage Systems is working with MCL flash for enterprise-class storage. The drivers are the performance and the need for lower power operations. All of the other enterprise requirements like reliability and endurance remain. In fact, the drives have to go through full qualifications for their tier-1 customers.
The rationale for moving to flash is performance, but single-cell flash is too expensive and MLC devices suffer from reliability and endurance issues compared to SLC. The company's Guardian technologies offer the combination of performance, reliability, endurance, and affordability into a single package.
FlashGuard extends the native endurance of standard MLC flash-based SSDs from less than 1 capacity write per day to 50 full capacity writes per day for a period of five years. The individual memory chips are fully characterized and optimized parameters are set for each chip. This advanced signal processing constantly monitors the operating parameters and adjusts them as required to maintain maximum operating life from the entire drive.
The flash management also looks at the entire drive, and not just a collection of similar cells. This analysis moves data into the "stronger" cells and uses the higher retention cells more often than the low retention cells. The core IP for this process is to take off-the-shelf MLC and adjust the drive write patterns and strengths to match the cell properties. As a result, the retention time and reliability are enhanced.
DataGuard technology protects user data from corruption along all data paths in the SSD, and provides the ability to recover data from failed page and NAND blocks. This signal processing is used to provide error detection and correction to the data moving to or from the drive. In addition, the drives use redundancy to improve the overall reliability. Both of these capabilities are the result of years of experience with HDDs, which have similar error characteristics.
EverGuard technology protects against loss of user data in the event of unexpected power interruptions. The addition of discrete poly-tantalum caps to the drive provide sufficient power backup capabilities to allow the drive to complete any write operations before the drive shuts down.
All of the performance and data integrity would be useless if the I/Os were not up to the task. Users want a choice of interfaces, but the enterprise is moving from PCIe and SATA to SAS (serial attached SCSI) for its greater flexibility and higher transfer rates. The users want the choices, but also want the performance and data integrity. Other interfaces will still be viable and useable for a long time, as the migration is at the replacement rate and not as a wholesale technology upgrade.
The adoption of SSDs is also restricted by network topologies. The tiered structure of storage, until now, has placed the SSDs in the front of the storage array as a cache. Now, SSDs are starting to be used as primary storage and the tiered structure is becoming an all flash entity. The active data are moving into the SSDs, while the slower and backup data are on some SATA drive.
The 10k and 15k enterprise drives are being replaced with the flash drives in all of the enterprises markets. The adoption rate is no longer constrained by the drive capacities. Instead, it now depends upon the normal conversion cycle which has been about 5 years.
The changes in storage will have an impact on the rest of the compute systems. Because the SSDs are not required to maintain a form factor, the architecture of servers and high performance computers will change to take advantage of the increased performance and lower power associated with the SSDs compared to the HDDs. The first units will have to connect to the existing hardware, and, therefore must be plug-in replacements, but the next generation systems will come from new companies and OEMs with flexibility.
The enterprise users want to change to the new storage systems for any number of reasons. Fast flash-based storage will move to both the end points and the data centers, and even will be a factor in the cloud. The enhanced power management adds to the already lower power associates with flash. The market is experiencing a rapid shift to the SSDs and is projected to grow at a compound annual rate of over 50 percent.
The next generation drives may use TLC flash, but the application requirements need to be matched to the drive characteristics. The signal processing requirements will be more difficult and the speed may suffer as a result of the higher densities. For a change, now is a good time to be in the storage business.