Patent Application
20180275870
This invention relates to systems and methods for minimizing head seek movement and improving I/O performance of hard disk drives.
In today's storage architectures, hard disk drives are used extensively to store data. Such hard disk drives may provide most of the storage in many of today's tiered storage architectures. In such architectures, the “hotness” or “coldness” of data may be continually monitored so that it can be optimally placed on storage media. For example, “hot” (i.e., frequently accessed) data may be placed on faster, more expensive storage media (e.g., solid state drives) to improve I/O performance. “Cold” (i.e., less frequently accessed) data may be placed on slower, less expensive storage media (e.g., hard disk drives) with reduced I/O performance. As the temperature of the data changes, the data may be migrated between storage tiers to optimize I/O performance.
Although significant emphasis has been directed to efficiently placing data on storage tiers of a tiered storage system, little or no emphasis has been directed to efficiently placing data within a hard disk drive itself. As known to those of skill in the art, a hard disk drive typically includes one or more rotating disks (platters) coated with magnetic material. Magnetic heads mounted to a moving actuator arm may be used to read from and write to the platter surfaces. Due to the faster linear velocity of the outer tracks of the platters and the positioning of the heads and actuator arms, reading and writing from the outer tracks is typically must faster than reading and writing data from inner tracks. In some cases, reading and writing to the outer tracks may be four or five times as fast as reading and writing to the inner tracks. For this reason, critical and/or important data such as operating system files may be stored on the outer tracks of a hard disk drive to improve I/O performance.
In view of the foregoing, what are needed are systems and methods to more efficiently place data within a hard disk drive. Ideally such systems and methods will minimize head seek movement and improve I/O performance of the hard disk drive.
The invention has been developed in response to the present state of the art and, in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available systems and methods. Accordingly, the invention has been developed to minimize head seek movement and improve the I/O performance of hard disk drives. The features and advantages of the invention will become more fully apparent from the following description and appended claims, or may be learned by practice of the invention as set forth hereinafter.
Consistent with the foregoing, a method for minimizing head seek movement and improving I/O performance of a hard disk drive is disclosed herein. In one embodiment, such a method includes receiving data for writing to a disk array. The method determines a group of tracks of a disk drive to which to write the data. For example, an outer group of tracks may be used to store hotter data and an inner group of tracks may be used to store colder data. The boundary between the outer group of tracks and the inner group of tracks may be adjusted as needed. The method then selects a disk drive in the disk array having a read/write head that is currently reading or writing to the group of tracks. The method then writes the data to the group of tracks on the selected disk drive.
A corresponding system and computer program product are also disclosed and claimed herein.
In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which:
It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
The present invention may be embodied as a system, method, and/or computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention.
The computer readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage system, a magnetic storage system, an optical storage system, an electromagnetic storage system, a semiconductor storage system, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.
Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage system via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.
Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages.
The computer readable program instructions may execute entirely on a user's computer, partly on a user's computer, as a stand-alone software package, partly on a user's computer and partly on a remote computer, or entirely on a remote computer or server. In the latter scenario, a remote computer may be connected to a user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.
Aspects of the present invention may be described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, may be implemented by computer readable program instructions.
These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.
The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.
Referring to
As shown, the network environment 100 includes one or more computers 102, 106 interconnected by a network 104. The network 104 may include, for example, a local-area-network (LAN) 104, a wide-area-network (WAN) 104, the Internet 104, an intranet 104, or the like. In certain embodiments, the computers 102, 106 may include both client computers 102 and server computers 106 (also referred to herein as “hosts” 106 or “host systems” 106). In general, the client computers 102 initiate communication sessions, whereas the server computers 106 wait for and respond to requests from the client computers 102. In certain embodiments, the computers 102 and/or servers 106 may connect to one or more internal or external direct-attached storage systems 112 (e.g., arrays of hard-storage drives, solid-state drives, tape drives, etc.). These computers 102, 106 and direct-attached storage systems 112 may communicate using protocols such as ATA, SATA, SCSI, SAS, Fibre Channel, or the like.
The network environment 100 may, in certain embodiments, include a storage network 108 behind the servers 106, such as a storage-area-network (SAN) 108 or a LAN 108 (e.g., when using network-attached storage). This network 108 may connect the servers 106 to one or more storage systems 110, such as arrays 110a of hard-disk drives or solid-state drives, tape libraries 110b, individual hard-disk drives 110c or solid-state drives 110c, tape drives 110d, CD-ROM libraries, or the like. To access a storage system 110, a host system 106 may communicate over physical connections from one or more ports on the host 106 to one or more ports on the storage system 110. A connection may be through a switch, fabric, direct connection, or the like. In certain embodiments, the servers 106 and storage systems 110 may communicate using a networking standard such as Fibre Channel (FC) or iSCSI.
Referring to
In selected embodiments, the storage controller 200 includes one or more servers 206. The storage controller 200 may also include host adapters 208 and device adapters 210 to connect the storage controller 200 to host systems 106 and storage drives 204, respectively. Multiple servers 206a, 206b may provide redundancy to ensure that data is always available to connected hosts 106. Thus, when one server 206a fails, the other server 206b may pick up the I/O load of the failed server 206a to ensure that I/O is able to continue between the hosts 106 and the storage drives 204. This process may be referred to as a “failover.”
In selected embodiments, each server 206 may include one or more processors 212 and memory 214. The memory 214 may include volatile memory (e.g., RAM) as well as non-volatile memory (e.g., ROM, EPROM, EEPROM, hard disks, flash memory, etc.). The volatile and non-volatile memory may, in certain embodiments, store software modules that run on the processor(s) 212 and are used to access data in the storage drives 204. The servers 206 may host at least one instance of these software modules. These software modules may manage all read and write requests to logical volumes in the storage drives 204.
One example of a storage system 110a having an architecture similar to that illustrated in
Referring to
As further shown in
In order to reduce head seek movement and improve I/O performance of the hard disk drive 204, storage space on the platters 300 may be divided up into various groups of tracks (also referred to herein as “zones”). For example, an outer group 306 of tracks (as indicated by the shading) may be designated for storing “hot” data, while an inner group 308 of tracks (as indicated by the lack of shading) may be designated for storing “cold” data. The boundary between the inner group 306 of tracks and the outer group 308 of tracks may be adjusted as needed.
Additional or alternative divisions may be provided on the platters 300.
Alternatively, each of the groups of tracks may be designated to store data by time or events since this data is likely to be accessed together. For example, data that is likely to be accessed at a first time or during a first period (e.g., morning) may be stored in a first group 306, while data that is likely to be accessed at a second time or during a second period (e.g., evening) may be stored in a second group 308. Alternatively, data that is accessed in association with a first scheduled event (e.g., a first sales event for a first set of products) may be stored in a first group 306, while data that is accessed in association with a second schedule event (e.g., a second sales event for a second set of products) may be stored in a second group 308. In this way, data that is accessed at or near the same time (e.g., in close temporal proximity) may be stored in close spatial proximity on the platter 300 to minimize the distance the head 302 and actuator arm 304 must travel to access the data. This will ideally improve I/O performance. Dividing the storage space within a disk drive 204 into different groups of tracks may enable tiered storage to be implemented within a disk drive 204, as well as enable data to be migrated between the tiers as the characteristics (e.g., temperature, etc.) of the data changes.
Referring to
Referring to
As shown, the zone establishment module 600 may be configured to establish various zones (i.e., groups of tracks) on a disk drive platter 300. For example, a first zone, which may be made up of outer tracks, may be used to store “hot” data, and a second zone, which may be made up of inner tracks, may be used to store “cold” data. Other zones or divisions of storage space on the platter 300 are possible and within the scope of the invention.
The data reception module 602 may receive data to be written to a disk array 502 and a temperature determination module 604 may determine a temperature of the data. In certain embodiments, temperature information may be received with data from the host system 106 (as part of a write command, for example) or the temperature determination module 604 may analyze historical I/O statistics on the host system 106 and/or the storage system 110a to determine the temperature of the data.
Alternatively to determining the temperature of the data, the timing determination module 606 may determine timing associated with the data. That is, the timing determination module 606 may determine timing (e.g., evenings, mornings, weekdays, weekends, etc.) when the data will likely be accessed. This may enable the data to be placed on a disk drive 204 near other data that will likely be accessed at the same or similar time, thereby reducing head seek movement of the disk drive 204 on which the data is stored.
Alternatively to determining the temperature or timing associated with the data, the event determination module 608 may determine scheduled events associated with the data. In other words, the event determination module 608 may determine scheduled events that may correspond in time to needed access of the data. This may enable the data to be placed on the disk drive 204 near other data that will be accessed in association with the same scheduled event or events, thereby reducing head seek movement of the disk drive 204 on which the data is stored.
Once an associated temperature, timing, or scheduled event is determined for data to be written, the zone determination module 610 may determine an appropriate zone (i.e., group of tracks) on which to store the data. The head position module 612 may then determine the current head position for disk drives 204 in the disk array 502. In certain embodiments, this may be accomplished by analyzing data that is currently being read from or written to the disk drives 204 and determining if this data is located at or near the same location or group of tracks to which the received data needs to be written (based on its associated temperature, timing, event, etc.). In other embodiments, disk drives 204 may be configured to provide information to a storage controller 200 that indicates where the heads 302 of the disk drives 204 are currently positioned.
Based on the head position of each of the disk drives 204, the disk drive selection module 614 may select a disk drive 204 that has a head positioned at or near the tracks that the received data is designated to be written. In some cases, this may be the disk drive 204 whose head 302 is positioned closest to the tracks that the received data is designated to be written. The write module 615 may then write the data to the designated tracks or group of tracks on the selected disk drive 204.
The boundary adjustment module 616 may be configured adjust the boundary between zones (i.e., groups of tracks) as needed. In certain embodiments, this may occur dynamically as the need for storage space in each zone changes. The data reorganization module 618, by contrast, may be configured to reorganize data within a disk drive 204 or across disk drives 204. For example, as the temperature of data changes, the data may be migrated from one zone to another. In certain cases, this may include moving the data from one disk drive 204 to another if, for example, another disk drive 204 is currently reading or writing to a zone that is appropriate to store the data. This will ideally reduce or minimize head seek movement. In certain cases, this may cause the boundary adjustment module 616 to adjust the boundary between zones since the amount of storage space needed in each zone may change.
The flowcharts and/or block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer-usable media according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, may be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
