Managing metadata and data for a logical volume in a distributed and declustered system

摘要

Methods, apparatus and computer program products for a distributed system include dividing logical volume data into data subsets, and defining at least one distributedly storage configuration for the logical volume. Metadata for the logical volume is written to a first set of first metadata tables, and the first set of first metadata tables is divided into metadata subsets having a one-to-one correspondence with the data subsets. The metadata subsets are distributed among the multiple digital information devices, and the metadata is copied from the first set of first metadata tables to a second set of corresponding second metadata tables in a one-to-one correspondence with the first metadata tables. The second metadata tables are distributed among the multiple digital information devices, and upon modifying the metadata in a one of the first metadata tables while processing a storage request, the corresponding second metadata table is revised with the updated metadata.

主权项

1. A method, comprising:
arranging multiple storage devices and multiple digital information devices having respective memories to communicate within a network; dividing data of a logical volume into data subsets; defining, for the logical volume, at least one storage configuration for the data subsets distributed among the respective storage devices; writing metadata for the logical volume to a first set of first metadata tables, each of the first metadata tables configured as a master metadata table; dividing the first set of first metadata tables into metadata subsets having a one-to-one correspondence with the data subsets; distributedly storing the metadata subsets among the multiple digital information devices, the storage configuration of the data subsets independent from the storing of the metadata subsets; copying the metadata from the first set of first metadata tables to a second set of corresponding second metadata tables in a one-to-one correspondence with the first metadata tables, each of the second metadata tables configured as a backup metadata table; distributedly storing the second metadata tables among the multiple digital information devices so that a given first metadata table and the corresponding second metadata table are stored to a different one of the multiple digital information devices, and so that the corresponding second metadata tables for the first metadata tables on a first of the digital information devices are distributed among at least an additional two of the digital information devices; and upon modifying the metadata in a one of the first metadata tables while processing a storage request, updating the corresponding second metadata table with the updated metadata.