DESTAGING CACHE DATA USING A DISTRIBUTED FREEZER

摘要

Methods, apparatus and computer program products implement embodiments of the present invention that enable digital information devices having respective storage devices and memories to distributedly store, for a logical volume, data and first and second parity values across corresponding regions of the storage devices. Freezers having a one-to-one correspondence with the storage devices are distributedly stored in the memories. Upon detecting, in a cache, updated data for one or more first regions on the storage devices, existing data from the one or more first regions, and additional data for parity calculations are retrieved from one or more corresponding second regions on the storage devices, and first and the second parity values are calculated using the updated data, the existing data and the additional data, and the updated data and the calculated first and second parity values are stored to the freezers.

主权项

1. A method, comprising:
arranging multiple digital information devices having respective storage devices and memories to communicate within a network; distributedly storing, for a logical volume, data and first and second parity values across corresponding physical regions of the storage devices; distributedly storing, in the memories, multiple freezer nodes having a one-to-one correspondence with each of the multiple storage devices; detecting, in a cache for the logical volume, updated data for one or more first physical regions on the storage devices; retrieving existing data from the one or more first physical regions, and additional data for use in parity calculations from one or more corresponding second physical regions on the storage devices; calculating the first and the second parity values using the updated data, the existing data and the additional data; and storing the updated data and the calculated first and second parity values to the freezer nodes.