Abstract: One or more aspects of the present disclosure relate to recovering at least one failed disk. In embodiments, determining a storage reserve capacity allocated for recovering at least one storage device of a storage array is determined. Zero or more storage portions from each storage device of at least one storage cluster for disk recovery are adaptively assigned based on the storage reserve capacity. The failing and/or failed disk using the assigned storage portions is recovered in response to detecting a failing and/or failed disk.

Abstract: A storage array includes a scalable drive cluster and non-scaling drive clusters on which RAID (D+P) protection groups are implemented using partition as protection group members. The scalable drive cluster is scaled by adding one or more new drives and moving protection group members onto the new drives. Reserve capacity is calculated based on scaling of the scalable drive cluster by converting unused partitions to reserve capacity when the cluster is scaled. When W=(D+P) new drives are added to the storage array the reserve capacity is replenished, if any was used, by moving protection groups from the scalable drive cluster to a non-scaling drive cluster created with the W new drives. Maintaining the reserve capacity on the scaling drive cluster improves function of the storage array because unutilized reserve capacity can be relocated during scaling without moving data.

Abstract: A flexible RAID system can expand by iteratively adding disks to a disk cluster. The disks may be added individually or in groups. Spare capacity is distributed over multiple disks within a cluster. Clusters are created, grown, and divided with predictable RAID member distribution patterns. Cluster validation is performed based on the patterns.

Abstract: A subset of drives with protection groups that have D data members and P parity members is created with (W+1) drives each having W partitions where W=(D+P). A single partition protection group is created in the lowest numbered partition of the W lowest numbered drives. Spares are created at drive X partition Y that satisfy X+Y=W+2. Members of additional protection groups with W members are symmetrically distributed on remaining partitions such that the protection group member at drive X partition index Y belongs to protection group N: if (X+Y)<(W+2), then N=(X+Y?2); and if (X+Y)>(W+2), then N=(X+Y?W?2). The spares are used to rebuild partitions in the event of drive failure. When a new drive is added the first W protection group members in the lowest numbered unrotated partition are rotated onto the new drive. The single partition protection group is excluded from rotation. Partitions vacated by rotated protection group members and a rotated spare are used to create a new protection group.

Abstract: A storage array includes a scalable drive cluster and non-scaling drive clusters on which RAID (D+P) protection groups are implemented using partition as protection group members. The scalable drive cluster is scaled by adding one or more new drives and moving protection group members onto the new drives. Reserve capacity is calculated based on scaling of the scalable drive cluster by converting unused partitions to reserve capacity when the cluster is scaled. When W=(D+P) new drives are added to the storage array the reserve capacity is replenished, if any was used, by moving protection groups from the scalable drive cluster to a non-scaling drive cluster created with the W new drives. Maintaining the reserve capacity on the scaling drive cluster improves function of the storage array because unutilized reserve capacity can be relocated during scaling without moving data.

Abstract: A subset of drives with protection groups that have D data members and P parity members is created with (W+1) drives each having W partitions where W=(D+P). A single partition protection group is created in the lowest numbered partition of the W lowest numbered drives. Spares are created at drive X partition Y that satisfy X+Y=W+2. Members of additional protection groups with W members are symmetrically distributed on remaining partitions such that the protection group member at drive X partition index Y belongs to protection group N: if (X+Y)<(W+2), then N=(X+Y?2); and if (X+Y)>(W+2), then N=(X+Y?W?2). The spares are used to rebuild partitions in the event of drive failure. When a new drive is added the first W protection group members in the lowest numbered unrotated partition are rotated onto the new drive. The single partition protection group is excluded from rotation. Partitions vacated by rotated protection group members and a rotated spare are used to create a new protection group.

Abstract: Each drive in a cluster is organized into splits of a single size. The splits are used as protection group members for a selected RAID level. Individual clusters can be scaled up with a number of new drives that is less than the number of protection group members for the RAID level by redistributing some data/parity to splits of the new drives. Splits are selected for redistribution such that new protection groups are created. If the number of new drives is equal to or greater than the number of protection group members for the RAID level, then new clusters may be created using the new drives. Any remaining drives are used to scale-up individual clusters.

Abstract: In a storage system that implements RAID (D+P) protection groups a drive subset initially has (D+P) drives plus a spare drive with (D+P) splits. Spare splits are distributed with drive index and split index adjacency such that no single drive or split index contains multiple spare splits. When the drive subset is incremented by one drive a group of selected splits are relocated to the new drive based on drive index and split index adjacency such that no single drive or split index contains multiple members of a new protection group. If one of the drives is failing or fails, then an adjusted spare split index value is calculated for each protection group member on that drive so that the protection group members are rebuilt or relocated without placing more than one member of any protection group on a single drive. Adjusted spare split index values may be calculated in steps using the data split indices in ascending order and the largest drive indices in descending order.

Abstract: In a storage system that implements RAID (D+P) protection groups a drive subset initially has (D+P) drives with (D+P) partitions. The drive subset is made to be symmetrical such that protection group members are symmetrically distributed in a matrix of drive rows and partition columns that represents the drive subset. A single new drive is added by partitioning the new drive with (D+P) partitions, moving existing protection group members from a selected partition of the (D+P) drives to partitions of the single new drive by rotating the selected partition by 90 degrees, and adding protection group members of a new protection group to the vacated selected partition of the (D+P) drives. The process is repeated until (D+P) new drives have been added in single drive increments. The resulting drive subset is then split by forming a non-symmetric drive subset from the (D+P) drives and forming a symmetric drive subset from the (D+P) new drives.

Abstract: In a storage system that implements RAID (D+P) with an existing cluster of drives in which the drives have (D+P) partitions that are protection group members, cluster member transfer code creates a new drive cluster when fewer than D+P new drives are added to the storage system. The cluster member transfer code moves one or more drives from the existing cluster into a new cluster so that the number of new drives plus the number of moved drives equals D+P. One or more protection groups may be moved to the new cluster.

Abstract: Disks of equal storage capacity in a disk cluster have M*W partitions, where RAID width W=D+P. RAID (D+P) protection groups are implemented on the disks with protection group members stored in individual partitions. An amount of storage capacity equal to the storage capacity of one disk is distributed across multiple disks in spare partitions. The spare partitions may be distributed such that no more than one spare partition resides on a single disk. M may be selected to optimize rebuild latency. The protection group members of a failed disk are rebuilt in the distributed spare partitions and subsequently relocated to a provisional spare drive. The populated provisional spare drive replaces the failed drive.

Abstract: In a storage system that implements RAID (D+P) with an existing cluster of drives in which the drives have (D+P) partitions that are protection group members, cluster member transfer code creates a new drive cluster when fewer than D+P new drives are added to the storage system. The cluster member transfer code moves one or more drives from the existing cluster into a new cluster so that the number of new drives plus the number of moved drives equals D+P. One or more protection groups may be moved to the new cluster.

Abstract: Techniques for performing configuration may include: determining an initial distribution of logical devices among disk adapters, wherein the initial distribution assigns each logical device a designated disk adapter as a primary active disk adapter servicing I/Os directed to the logical device, wherein the logical devices have storage provisioned from a RAID group including physical storage devices, wherein the disk adapters concurrently issue I/Os to each of the physical storage devices; detecting a configuration change; and responsive to detecting a configuration change, performing first processing. The first processing may include determining, in accordance with the configuration change, a redistribution of the logical devices among the disk adapters; and draining pending I/Os. The configuration change may include adding or removing a logical device provisioned from the RAID group.

Abstract: Each drive in a cluster is organized into splits of a single size. The splits are used as protection group members for a selected RAID level. Individual clusters can be scaled up with a number of new drives that is less than the number of protection group members for the RAID level by redistributing some data/parity to splits of the new drives. Splits are selected for redistribution such that new protection groups are created. If the number of new drives is equal to or greater than the number of protection group members for the RAID level, then new clusters may be created using the new drives. Any remaining drives are used to scale-up individual clusters.

Abstract: Techniques for performing configuration may include: determining an initial distribution of logical devices among disk adapters, wherein the initial distribution assigns each logical device a designated disk adapter as a primary active disk adapter servicing I/Os directed to the logical device, wherein the logical devices have storage provisioned from a RAID group including physical storage devices, wherein the disk adapters concurrently issue I/Os to each of the physical storage devices; detecting a configuration change; and responsive to detecting a configuration change, performing first processing. The first processing may include determining, in accordance with the configuration change, a redistribution of the logical devices among the disk adapters; and draining pending I/Os. The configuration change may include adding or removing a logical device provisioned from the RAID group.

Abstract: A system and methods for imaging a patient organ. The system includes a MRI imaging apparatus communicating with a memory and processor. The method aligns the organ with a standardized organ, and includes a step of spatially normalizing the standardized organ to the patient organ. The method also provides optimized slices of the standardized organ and translates optimized slices of standardized organ into optimized slices of the patient organ. The method images the patient organ according to the optimized slices of the patient organ.