The claimed invention relates generally to the field of distributed data storage systems and more particularly, but not by way of limitation, to an apparatus and method for autonomous storage-centric control of data services in a storage system.
Computer networking began proliferating when the data transfer rates of industry standard architectures could not keep pace with the data access rate of the 80386 processor made by Intel Corporation. Local area networks (LANs) evolved to storage area networks (SANs) by consolidating the data storage capacity in the network. Users have realized significant benefits by the consolidation of equipment and the associated data handled by the equipment in SANs, such as the capability of handling an order of magnitude more storage than would otherwise be possible with direct attached storage, and doing so at manageable costs.
More recently the movement has been toward a network-centric approach to controlling the data storage subsystems. That is, in the same way that the storage was consolidated, so too are the systems that control the functionality of the storage being offloaded from the servers and into the network itself. Host-based software, for example, can delegate maintenance and management tasks to intelligent switches or to a specialized network storage services platform. Appliance-based solutions eliminate the need for the software running in the hosts, and operate within computers placed as a node in the enterprise. In any event, the intelligent network solutions can centralize such things as storage allocation routines, backup routines, and fault tolerance schemes independently of the hosts.
While moving the intelligence from the hosts to the network resolves some problems such as these, it does not resolve the inherent difficulties associated with the general lack of flexibility in altering the presentation of virtual storage to the hosts. For example, stored data may need to be moved for reliability concerns, or more storage capacity may need to be added to accommodate a growing network. In these events either the host or the network must be modified to make it aware of the existence of the new or changed storage space. What is needed is an intelligent data storage subsystem that self-deterministically allocates, manages, and protects its respective data storage capacity and presents that capacity as a virtual storage space to the network to accommodate global storage requirements. This virtual storage space is able to be provisioned into multiple storage volumes. A distributed computing environment uses these intelligent storage devices for global provisioning as well as for global sparing in the event of failures. It is to this solution that embodiments of the present invention are directed.
Embodiments of the present invention are generally directed to a storage-centric subsystem in a distributed storage system with each subsystem autonomously controlling its own data storage and retrieval services.
In some embodiments a self-contained data storage subsystem is provided for a distributed storage system having a plurality of rotatable spindles, each supporting a storage medium adjacent a respective independently moveable actuator in a data storing and retrieving relationship therewith; and a subsystem processor adapted for mapping a virtual storage volume to the plurality of mediums for use by a remote device of the distributed storage system.
In some embodiments a data storage subsystem is provided for a distributed storage system having a self-contained plurality of discrete data storage devices, and a subsystem processor communicating with the data storage devices and adapted for abstracting a command received from a remote device and associating related memory accordingly.
In some embodiments a distributed storage system is provided having a host, and a backend storage subsystem in communication with the host over a network and comprising means for virtualizing a self-contained storage capacity independently of the host.
These and various other features and advantages which characterize the claimed invention will become apparent upon reading the following detailed description and upon reviewing the associated drawings.
It is further contemplated that the A host computer 102 and the A intelligent data storage subsystem 108 can be physically located at a first site, the B host computer 102 and B intelligent data storage subsystem 108 can be physically located at a second site, and the C host computer 102 can be yet at a third site, although such is merely illustrative and not limiting. All entities on the distributed computer system are connected over some type of computer network.
Aspects of the managed reliability include invoking reliable data storage formats such as RAID strategies. For example, by providing a system for selectively employing a selected one of a plurality of different RAID formats creates a relatively more robust system for storing data, and permits optimization of firmware algorithms that reduce the complexity of software used to manage the MDA 118 as well as resulting in relatively quicker recovery from storage fault conditions. These and other aspects of this multiple RAID format system is described in patent application Ser. No. 10/817,264 entitled Storage Media Data Structure and Method which is assigned to the present assignee and incorporated herein by reference.
Managed reliability can also include scheduling of diagnostic and correction routines based on a monitored usage of the system. Data recovery operations are executed for copying and reconstructing data. The subsystem processor is integrated with the MDAs 118 in such as way to facilitate “self-healing” of the overall data storage capacity without data loss. These and other aspects of the managed reliability aspects contemplated herein are disclosed in patent application Ser. No. 10/817,617 entitled Managed Reliability Storage System and Method which is assigned to the present assignee and incorporated herein by reference. Other aspects of the managed reliability include responsiveness to predictive failure indications in relation to predetermined rules, as disclosed for example in patent application Ser. No. 11/040,410 entitled Deterministic Preventive Recovery From a Predicted Failure in a Distributed Storage System which is assigned to the present assignee and incorporated herein by reference.
The policy processor 164 can be programmed to execute desired operations via the ISP 150. For example, the policy processor 164 can communicate with the list managers 182, 184, that is send and receive messages, via the CPS 186. Responses to the policy processor 164 can serve as interrupts signaling the reading of memory 168 registers.
For present purposes, the term “virtual storage volume” means a logical entity that generally corresponds to a logical abstraction of physical storage. “Virtual storage volume” can include, for example, an entity that is treated (logically) as though it was consecutively addressed blocks in a fixed block architecture or records in a count-key-data architecture. A virtual storage volume can be physically located on more than one storage element.
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The sealed MDA 118A also allows the manufacturer to maximize the reliability and fault tolerance of the group of storage medium within. This is done by optimizing the drives in the multi-spindle arrangement. Design Optimizations are allowed within to reduce cost, increase performance, increase reliability, all toward the extended life of the data within the MDA 118A. The MDA 118A is itself a basis for further refinement of the abstract protected storage container. Furthermore, the design of the MDA 118 itself provides an almost zero rotational vibration and high cooling efficiency environment. This allows the storage medium within to be manufactured to less costly standards without compromising the MDA 118 reliability, performance, or capacity. The sealed MDA 118A thus provides no single point of failure and near perfect rotational vibration avoidance and cooling efficiency. This allows designing the MDA 118A for optimal disc medium characteristics, and reduces cost while at the same time increasing reliability and performance.
In summary, a self-contained data storage subsystem (such as 108) for a distributed storage system (such as 100) is provided, including a plurality of rotatable spindles (such as 142) each supporting a storage medium (such as 140) adjacent a respective independently moveable actuator (such as 143) in a data storing and retrieving relationship with the storage medium. The data storage subsystem further includes a subsystem processor (such as 150) adapted for mapping a virtual storage volume to the plurality of mediums for use by a remote device (such as 102) of the distributed storage system.
In some embodiments the subsystem has the plurality of spindles and mediums contained within a common sealed housing (such as 190, 192). Preferably, the subsystem processor allocates memory in the virtual storage volume for storing data in a fault tolerant manner, such as in a RAID methodology. The processor is furthermore capable of performing managed reliability methodologies in the data storage process, such as initiating in-situ deterministic preventive recovery steps in response to an observed predicted storage failure. Preferably, the data storage subsystem is made of a plurality of data storage devices (such as 128) each having a disc stack made of two of more discs of data storage medium.
In other embodiments data storage subsystem is contemplated for a distributed storage system comprising a self-contained plurality of discrete data storage devices and a subsystem processor communicating with the data storage devices and adapted for abstracting a command (such as in
In alternative embodiments a distributed storage system is provided comprising a host; and a backend storage subsystem in communication with the host over a network and comprising means for virtualizing a self-contained storage capacity independently of the host.
The means for virtualizing can be characterized by a plurality of discrete individually accessible data storage units. The means for virtualizing can be characterized by mapping a virtual block of storage capacity associated with the plurality of data storage units. The means for virtualizing can be characterized by sealingly containerizing the plurality of data storage units and associated controls. The means for virtualizing can be characterized by storing data in a fault tolerant manner, such as without limitation to RAID methodology. The means for virtualizing can be characterized by initiating in-situ deterministic preventive recovery steps in response to an observed predicted storage failure. The means for virtualizing can be characterized by a multiple spindle data storage array.
For purposes herein the term “means for virtualizing” expressly does not contemplate previously attempted solutions that included the system intelligence for mapping the data storage space anywhere but within the respective data storage subsystem. For example, “means for virtualizing” does not contemplate the use of a storage manager to control the functions of data storage subsystems; neither does it contemplate the placement of the manager or switch within the SAN fabric, or within the host.
It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and function of various embodiments of the invention, this detailed description is illustrative only, and changes may be made in detail, especially in matters of structure and arrangements of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, the particular elements may vary depending on the particular processing environment without departing from the spirit and scope of the present invention.
In addition, although the embodiments described herein are directed to a data storage array, it will be appreciated by those skilled in the art that the claimed subject matter is not so limited and various other processing systems can be utilized without departing from the spirit and scope of the claimed invention.