Abstract: Provided are a processor generates second notification information by copying first notification information including target information about all communication adaptors in a storage apparatus; updates the first notification information, upon configuration information on the communication adaptors being modified; updates, when receiving a target information obtainment request, the second notification information with second notification information; blocks, when a predetermined copy prevention condition is met, copy of the first notification information to the second notification information; and sends, when receiving the target information obtainment request, the second notification information to the host apparatus, thereby, the load for notifying notification information to the host apparatus can be reduced, as well as preventing any inconsistency in notifying the notification information.

Abstract: In a computer-implemented data storage system comprising at least one storage control and data storage, wherein data is stored in the form of volumes, at least a plurality of volumes having at least some freespace, and a grouping of a plurality of volumes comprises a pool. In response to a defragmentation request, the storage control initiates migration of data from a pool to generate additional freespace. Subsequent to the migration of data, fragmentation of data of the pool is computed, and the amount of existing freespace of the pool is determined. The amount of existing freespace is compared to a freespace threshold, where the freespace threshold is related to the computed fragmentation. If the comparison indicates the amount of freespace is below the threshold, spill volumes are added to the pool; and, else, the pool is kept intact without adding spill volumes. Then, defragmentation of the pool is initiated.

Abstract: A method includes determining a capacity model that configures computing resource capacity for a capacity container. The computing resource capacity includes a first storage attribute for an amount of storage in a storage component. A load model is determined that configures load for the capacity container. The load includes a second storage attribute for a storage requirement for a virtual machine. A profile of a virtual machine unit is determined for estimating available capacity in a capacity container. The profile is determined using virtual machine attributes for a set of virtual machines, wherein the virtual machine unit includes a storage requirement based on storage requirements for the set of virtual machines. The profile of the virtual machine unit is fit into available capacity. A number of virtual machine units is determined based on the fitting, the number of virtual machine units being a measure of available capacity.

Abstract: In a computer-implemented data storage system comprising at least one storage control and data storage, wherein data is stored in the form of volumes, at least a plurality of volumes having at least some freespace, and a grouping of a plurality of volumes comprises a pool. In response to a defragmentation request, the storage control initiates migration of data from a pool to generate additional freespace. Subsequent to the migration of data, fragmentation of data of the pool is computed, and the amount of existing freespace of the pool is determined. The amount of existing freespace is compared to a freespace threshold, where the freespace threshold is related to the computed fragmentation. If the comparison indicates the amount of freespace is below the threshold, spill volumes are added to the pool; and, else, the pool is kept intact without adding spill volumes. Then, defragmentation of the pool is initiated.

Abstract: A method of estimating a read level for a memory device includes calculating first information corresponding to at least one among information about the number of cells having a particular logic level in data to be programmed and information about the number of cells having a particular cell state and storing the first information during a program operation; reading the data based on a threshold level that has been set and calculating second information about the number of cells in at least one state defined by the threshold level with respect to the read data; calculating third information about the number of cells in the at least one state, which corresponds to the second information, using a probability based on the first information; comparing the second information with the third information; and determining whether to change the threshold level according to the comparison result.