摘要:
A method for implementing virtual disk reservations on a storage media for multiple distributed applications. The method includes initializing a plurality of virtual disks, wherein each of the virtual disks is instantiated on a physical storage media. A reservation status is determined for each of the virtual disks and a first distributed application that uses at least one virtual disk is executed. Upon an update of the reservation status for the at least one virtual disk by the first distributed application, a notification indicator is set to notify a second distributed application of the update. The update is subsequently recognized and the notification indicator is cleared in order to continue I/O for the first distributed application and the second distributed application.
摘要:
Techniques for updating a cached version of data in a computer system upon a change of the data as stored in a shared storage system networked to the computer system are described. In accordance with such techniques, a notification from the shared storage system is received at the computer system upon attempting to access the shared storage system. The computer system then determines that the notification occurred due to an unregistering of the computer system's access to the shared storage system by a second computer system that has updated the data stored in the shared storage system. As such, the computer system re-registers its access to the shared storage system and updates the cached version of the data with the data in the shared storage system that was updated by the second computer system.
摘要:
A method and system is provided for initializing files such as, for example and without limitation, pre-allocated files or raw device mapping (RDM) files, by delaying initializing file blocks. In accordance with one or more embodiments of the present invention, file blocks are associated with corresponding indicators to track un-initialized blocks.
摘要:
A computer has access to a system-formatted data storage unit (DSU) containing a file system and to a raw DSU. A file within the file system constitutes a raw DSU mapping that facilitates access to the raw DSU. The raw DSU mapping appears to be an ordinary file to a storage user, but with the size of the raw DSU. An attempted access to the raw DSU mapping is translated into a corresponding access to the raw DSU. Access to the raw DSU by the storage user may be restricted to a specified region of the raw DSU, by defining an extent within the raw DSU mapping. The raw DSU mapping provides access to the raw DSU with many of the advantages of using a file system, including name persistency, permissions, persistent attributes, locking information for a distributed file system and other extended metadata.
摘要:
A method and system is provided for initializing files such as, for example and without limitation, pre-allocated files or raw device mapping (RDM) files, by delaying initializing file blocks. In accordance with one or more embodiments of the present invention, file blocks are associated with corresponding indicators to track un-initialized blocks.
摘要:
Multiple computers are connected to a data storage unit that includes a file system, which further includes multiple data entities, including files, directories and the file system itself. The file system also includes, for each data entity, an owner field for indicating which computer, if any, has exclusive or shared access to the data entity, along with a time field for indicating when a lease of the data entity began. When a computer wants to lease a data entity, the computer uses a disk reservation capability to temporarily lock the data storage unit, and, if the data entity is not currently leased, the computer writes its own identification value into the owner field and a current time into the time field for the data entity, to claim the data entity for a renewable lease period. If a prior lease of a data entity has expired, another computer may break the lease and claim ownership for itself.
摘要:
Multiple computers are connected to a data storage unit that includes a file system, which further includes multiple data entities, including files, directories and the file system itself. The file system also includes, for each data entity, an owner field for indicating which computer, if any, has exclusive or shared access to the data entity, along with a time field for indicating when a lease of the data entity began. When a computer wants to lease a data entity, the computer uses a disk reservation capability to temporarily lock the data storage unit, and, if the data entity is not currently leased, the computer writes its own identification value into the owner field and a current time into the time field for the data entity, to claim the data entity for a renewable lease period. If a prior lease of a data entity has expired, another computer may break the lease and claim ownership for itself.
摘要:
A computer has access to a system-formatted data storage unit (DSU) containing a file system and to a raw DSU. A file within the file system constitutes a raw DSU mapping that facilitates access to the raw DSU. The raw DSU mapping appears to be an ordinary file to a storage user, but with the size of the raw DSU. An attempted access to the raw DSU mapping is translated into a corresponding access to the raw DSU. Access to the raw DSU by the storage user may be restricted to a specified region of the raw DSU, by defining an extent within the raw DSU mapping. The raw DSU mapping provides access to the raw DSU with many of the advantages of using a file system, including name persistency, permissions, persistent attributes, locking information for a distributed file system and other extended metadata.
摘要:
A method for implementing virtual disk reservations on a storage medium for multiple distributed applications. The method includes initializing a plurality of virtual disks, wherein each of the virtual disks is instantiated on a physical storage medium. A reservation status is determined for each of the virtual disks and a first distributed application that uses at least one virtual disk is executed. Upon an update of the reservation status for the at least one virtual disk by the first distributed application, a notification indicator is set to notify a second distributed application of the update. The update is subsequently recognized and the notification indicator is cleared in order to continue I/O for the first distributed application and the second distributed application.
摘要:
In a computer system running at least a first virtual machine (VM) and a second VM on virtualization software, a computer implemented method for the second VM to provide quasi-lockstep fault tolerance for the first VM. The method includes enabling operations of the second VM to diverge from being in lockstep with operations with the first VM without resynchronizing the second VM with the first VM, if output of the second VM is not diverging from output of the first VM. The output of the second VM is compared with the output of the first VM to determine whether the output of the second VM has diverged from the output of the first VM. In response to a determination that the output of the second VM has diverged from the output of the first VM, a resynchronization of the second VM is executed.