Dot Hill Assigned Four Patents

Dot Hill Systems Corp. announced four new additions to its patent portfolio that describe innovations that make it easier for organizations to increase storage capacity, safeguard data assets and reduce power costs.

Writing distinct data to snapshot clones
Inventions described in 93rd US patent, numbered 8,656,123, preserves snapshots during data cloning. Snapshots provide a versatile feature that is useful for backup and data recovery. However, traditional snapshots are read-only accessible and their contents cannot be modified, which limits their usability. A relatively recent advance in backup facilities is the ability to ‘clone’ an existing snapshot, and perform a backup of the clone instead of the active file system. Clones, however, have the same read-only restrictions imposed on them as their parent snapshots and those that do not have read-only restrictions cannot be counted on to represent the actual point-in-time that the snapshot was taken. Dot Hill’s innovation provides a clone snapshot with a separate write area. This allows host computers and applications to write unique data to the clone snapshot, separate from any other snapshot or the storage volume. Additionally, multiple concurrent clone snapshots may be created and maintained by the storage controller. This allows independent testing and evaluation to be conducted without altering either the storage volume or the regular (non-clone) snapshots.

Adding storage capacity without powering down the system
Unlike previous methods that take storage devices offline while a RAID array is being expanded, 94th US patent, numbered 8,656,131, describes technology that allows full read and write access to the array during the addition of a JBOD expansion chassis. Thos innovation also allows immediate access to the new capacity before the array data has been reordered. The invention can be used for multiple RAID arrays including both parity and non-parity arrays. The memory required for temporary storage during the reconfiguration operation may be provided either in the storage controller itself or in free space in any connected storage device.

Protecting data at reduced cost during power outages
The inventions in 95th US patent, numbered 8,694,812, allows lower-powered backups using small super-capacitors, in the event of a power outage. When main power is lost, Dot Hill controllers move data and metadata in the storage controller volatile memory to onboard non-volatile memory. Backup power must be provided to the volatile memory, the memory controller, and the non-volatile memory during the backup process. Once moved to the non-volatile memory, the backup power is shut down until main power is restored. The data and metadata are safe in non-volatile memory and can remain there indefinitely. This innovation saves power by moving the data and metadata in stages between volatile and non-volatile memory, and putting the volatile memory into a low-power self-refresh mode while the slower non-volatile memory is storing the data and metadata. This reduces the power required to move all of the data and metadata from the volatile memory, which means a smaller or less expensive backup power source may be used, compared to conventional approaches.

Simplifying the addition and removal of drives
In the past, storage device modules have required levers and other mechanical devices, which add complexity and cost to storage arrays. Dot Hill’s engineers have removed many of these unnecessary components with innovations described in the company’s 96th US patent number 8,717,753, resulting in a simpler design with fewer parts that weighs less and saves space and costs. Now storage device modules can be inserted with a simple push of the hand. To remove the module from the chassis, a user slides a finger lever horizontally across the front. An ejection spring ejects the storage device, allowing a user to safely and easily remove modules from the storage chassis. This compact design eliminates bulky bezels and the need for additional space requirements.

“Our extensive patent portfolio and the real-world innovations that we implement to solve users’ daily storage challenges are a result of Dot Hill’s world-class engineering team,” said Ken Day, CTO, Dot Hill. “In addition to 99.999% data availability, we are perpetually devising ways to make AssuredSAN storage solutions easier and more practical than competitive offerings.”