Abstract: Method and system for handling error events on a current path for processing an I/O request for reading information from and writing information to a storage space is provided. A system is able to communicate with the storage space via more than one path. If the current path reports an error event, then an alternate path quality is determined to ascertain whether the alternate path will generate an error similar to the current path. The alternate path quality is determined based on a plurality of factors which are assigned certain weights. The weights are determined based on a likely contribution of each factor to a repetition of the error reported by the current path. If the alternate path quality is equal to or exceeds a programmable threshold value, then the alternate path is selected.

Abstract: In one embodiment, the present invention provides an ability to handle an error occurring during a memory migration operation in a high availability system. In addition, a method can be used to dynamically remap a memory page stored in a non-mirrored memory region of memory to a mirrored memory region. This dynamic remapping may be responsive to a determination that the memory page has been accessed more than a threshold number of times, indicating a criticality of information on the page. Other embodiments are described and claimed.

Abstract: To manage physical paths between a server system and a storage system and information about routing between virtual machines and virtual storage systems in an integrated fashion. A computer system of the present invention includes: a computer and a storage system that stores data, in which the computer includes first information for managing the first resource relating to the computer; and the storage system includes second information for managing the second resource provided in the storage system, and in which a relation between the virtual machine and the virtual storage system is defined based on the first information and the second information.

Abstract: A system includes a first database, a second database, a third database, and an application server. The first database server includes a database instance. The second database server is in communication with the first database server. The second database server includes a mirror of the database instance. The third database server is in communication with the second database server. The third database server is configured to store a copy of a database within the database instance. The application server is configured to be placed in communication with the first, second, and third database servers, configured to fail over between the first and second database servers, and further configured to fail over between the second and third database servers.

Abstract: The present invention discloses devices Including a transparent client-connection manager for exchanging client data between an application server and the device: a request analyzer for analyzing query requests from at least one application server; a data-retrieval/command-execution module for executing query requests; a database connection manager for exchanging database data between at least one database server and the device: a cache-memory pool for storing data items from at least one database server: a cache-policy module for determining cache criteria for storing the data Items In the cache-memory pool; and a data-consistency invalidation module for determining invalidated data Items based on invalidation criteria for removing from the cache-memory pool. The cache-memory pool Is configured to utilize memory modules residing in data proxy devices and distributed cache management utility, enabling the memory capacity to be used as a cluster to balance workloads.

Abstract: Described is a technology by which an owner node in a server cluster maintains ownership of a storage mechanism through a persistent reservation mechanism, while allowing non-owning nodes read and write access to the storage mechanism. An owner node writes a reservation key to a registration table associated with the storage mechanism. Non-owning nodes write a shared key that gives them read and write access. The owner node validates the shared keys against cluster membership data, and preempts (e.g., removes) any key deemed not valid. The owner node also defends ownership against challenges to ownership made by other nodes, so that another node can take over ownership if a (formerly) owning node is unable to defend, e.g., because of a failure.

Abstract: The methods and structure herein provide for expanding the storage capacity of a RAID storage system while maintaining the same level of RAID storage management. A RAID storage controller may be coupled between a host computer and a RAID storage volume. The RAID storage controller manages the disk drives of the storage volume to present a single logical volume of storage to the host computer. When a storage expansion is desired, the RAID storage controller may communicatively couple to at least one expansion disk drive and begin transfer of data from the original RAID storage volume to the expansion disk drive(s). During this data transfer, read and write operations are continued to the original RAID storage volume. Additionally, the RAID storage controller duplicates write operations to the expansion disk drive(s) such that general storage operations required by the host computer are continued.

Abstract: This embodiment (a system) addresses and reduces the RAID build time by only rebuilding the used blocks and omitting the unused blocks. This starts after a disk drive from a RAID system is failed and replaced and storage controller starts the process of rebuilding the data on the new disk drive. Storage controller determines the logical volumes that must be rebuilt, send a message requesting only used blocks for these logical volumes from the volume manager and then uses this information and only rebuild the used blocks for the failed disk system.