The invention relates to methods and systems for on-demand configuration of logical storage volumes.
When a volume within a storage subsystem runs out of space, the host using the volume will need additional storage to continue I/O operations. The conventional method of manually configuring storage space by creating and assigning a new volume to the host or increasing the capacity of an existing volume is time consuming and risks causing significant downtime.
Aside from manual configuration, another technique sometimes used is called thin provisioning. With thin provisioning, a user can create a volume specifying a size but physical storage is only allocated to the volume as data is written. However, once the allocated capacity reaches the originally requested capacity for the volume, no more data can be written to the volume until it is re-sized, thus resulting in the need to manually add capacity to the volume.
A method for implementing on-demand configuration of a logical storage volume is provided. The method monitors the available storage capacity of a logical volume, and compares an actual logical volume utilization with a logical volume utilization threshold (such as a percentage of available logical storage space). If the actual logical volume utilization is greater than the logical volume utilization threshold, the method determines whether configured, physical storage space is available. If configured physical storage space is available, the method then reconfigures the logical volume to include the configured physical storage space.
If configured physical storage space is not available, the method locates unconfigured physical storage space, configures the available physical storage space, and reconfigures the logical volume using the configured physical storage space. If unconfigured physical space is not available, the method provides notice that a physical storage space limitation has been reached.
The invention will be better understood from a reading of the following detailed description taken in conjunction with the drawings in which like reference designators are used to designate like elements, and in which:
This invention is described in preferred embodiments in the following description with reference to the Figures, in which like numbers represent the same or similar elements. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are recited to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
The schematic flow chart diagram included is generally set forth as a logical flow-chart diagram (e.g.,
Referring to
In certain embodiments, storage controller 240 communicates with the plurality of data storage devices 180 via device adapters 165 and 175, and with plurality of data storage devices 190 via device adapters 166 and 176, using an I/O protocol selected from the group consisting of SCSI (Small Computer System Interface), iSCSI (Internet SCSI), SAS (Serial Attach SCSI), Fibre Channel, SCSI over Fibre Channel, Ethernet, Fibre Channel over Ethernet, Infiniband, and SATA (Serial ATA).
In the illustrated embodiment of
In the illustrated embodiments of
Referring now to
Each host adapter may include one or more Fibre Channel ports, one or more FICON ports, one or more ESCON ports, or one or more SCSI ports. Each host adapter is connected to both clusters 101A and 101B through interconnect bus 121 such that each cluster can handle I/O from any host adapter, and such that the storage controller portion of either cluster can monitor the communication path error rate for every communication path, physical and/or logical, interconnected with data storage library 100.
Storage controller portion 130 includes processor 132, computer readable medium 133, cache 134, and nonvolatile storage (“NVS”) 136. In certain implementations, computer readable medium 133 includes random access memory. In certain implementations, computer readable medium 133 includes non-volatile memory.
Storage controller portion 140 includes processor 142, computer readable medium 133, cache 144, and NVS 146. In certain embodiments, computer readable medium 143 includes random access memory. In certain embodiments, computer readable medium includes non-volatile memory.
I/O portion 160 includes a plurality of device adapters, such as device adapters 165, 166, 167, and 168. I/O portion 170 further includes a plurality of device adapters, such as device adapters 175, 176, 177, and 178.
In certain embodiments of the system, one or more host adapters, storage controller portion 130, and one or more device adapters, are packaged together on a single card disposed in the data storage system. Similarly, in certain embodiments, one or more host adapters, storage controller portion 140, and one or more device adapters, are disposed on another card disposed in the data storage system. In these embodiments, system 100 includes two cards interconnected with a plurality of data storage devices.
In the illustrated embodiment of
In certain embodiments, arrays 180 and/or 190 utilize a RAID (Redundant Array of Independent Disks) protocol. In certain embodiments, arrays 180 and/or 190 include what is sometimes called a JBOD array, i.e. “Just a Bunch Of Disks” where the array is not configured according to RAID. As those skilled in the art will appreciate, a RAID rank includes independent disk drives configured in an array of disk drives to obtain performance, capacity and/or reliability that exceeds that of a single large drive.
Referring now to
In step 310 the method sets a logical volume utilization threshold for the logical volume of step 310. In certain embodiments, step 305 is performed by a storage services provider. In certain embodiments, step 310 is performed by a storage controller, such as storage controller 100 (
In certain embodiments, the threshold volume usage of step 310 comprises a percentage of the nominal storage capacity of the logical storage volume. In certain embodiments, the threshold volume usage of step 310 comprises a specified storage level, i.e. 1 gigabyte (“GB”).
In step 320, Applicants' method determines an actual logical volume utilization for the logical volume of step 305. In certain embodiments, the determination of step 320 is performed via polling of the logical volume at one or more specified time intervals. In other embodiments, the determination of step 320 results when a certain event occurs indicating that the logical volume is reaching full capacity. In certain embodiments, step 320 is performed by a storage services provider. In certain embodiments, step 320 is performed by a storage controller, such as storage controller 100 (
In step 330, Applicants' method determines whether the logical volume is reaching an out-of-space condition by determining if the actual logical volume utilization of step 320 is greater than the logical volume utilization threshold of step 310. For example, if the logical volume utilization threshold is set at “80%, and if a logical volume is configured to comprise 1 GB, then Applicants' method would consider the logical volume to be reaching the out-of-space condition if the actual storage usage of step 310 is 800 megabytes or greater. Although the above example provides a percentage of allocated space as the predetermined threshold value, it is to be appreciated that the predetermined threshold value could, for example, be an amount of allocated space or any other indication of an out-of-space condition.
If the method determines in step 330 that the actual storage usage of step 310 is not greater than the threshold volume usage of step 305, then the method continues monitoring the logical volume. Alternatively, the method determines in step 320 that the actual logical volume utilization of step 320 is greater than the logical volume utilization threshold of step 310, the method transitions to step 340 and determines if configured, physical storage space is available. In certain embodiments, by “configured physical space” Applicants mean storage space that has been configured to utilize a RAID data storage protocol.
In certain embodiments, step 340 is performed by a storage services provider. In certain embodiments, step 340 is performed by a storage controller, such as storage controller 100 (
If the method determines in step 340 that configured physical space is available, then the method transitions from step 340 to step 350 wherein the method reconfigures the logical volume of step 305 to include all or a portion of the additional available configured physical space. In certain embodiments, step 350 is performed by a storage services provider. In certain embodiments, step 350 is performed by a storage controller, such as storage controller 100 (
Alternatively, if the method determines in step 340 that no available configured physical space exists then, in step 360 Applicants' method determines if non-configured physical space is available. In certain embodiments, step 360 comprises providing a query from a host computer to a storage controller external to said host computer. In certain embodiments, step 360 is performed by a storage services provider. In certain embodiments, step 360 is performed by a storage controller, such as storage controller 100 (
If the method determines in step 360 that physical storage space exists which can be appropriately configured (e.g., configured according to the RAID 5 protocol), then the method transitions from step 360 to step 370 and configures this physical space. In certain embodiments, step 370 is performed by a storage services provider. In certain embodiments, step 370 is performed by a storage controller, such as storage controller 100 (
If the method determines in step 360 that available storage space cannot be found, the method transitions from step 360 to step 380 wherein the method provides a message that a physical storage limit is met. In certain embodiments, step 370 is performed by a storage controller, such as storage controller 100 (
In step 390, the method provides additional physical storage space. In certain embodiments, step 390 comprises detecting additional physical storage space. In certain embodiments, step 390 is performed by a storage services provider. In certain embodiments, step 390 is performed by a storage controller, such as storage controller 100 (
Preferably, steps 310-380 (
While the preferred embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims.