Patent ID: 8818936
Filing Date: 2014-08-26
Classification: G06F

Abstract:
1. A method for processing read requests received during a protected restore operation, the method comprising: in a data storage system having a first portion of data denominated as a source and at least a second portion of data denominated as a clone, wherein the clone receives data from the source through synchronous mirroring until fracturing occurs after which the clone has data content that is a point-in-time copy of data content of the source and during a protected restore operation that includes copying at least a portion of the data content of the clone to the source, wherein during the protected restore operation the data content of the clone is prevented from being modified: receiving a read request to read data from the source; determining whether to redirect the read request to the clone, wherein determining whether to redirect the read request to the clone includes determining whether the read request requests data that has yet to be copied from the clone to the source; and in response to determining to redirect the read request to the clone, redirecting the read request to read the data from the clone via a stack on the clone, wherein data is read from the source for a subsequent read request during the protected restore operation.