公开(公告)号：US11467757B1

公开(公告)日：2022-10-11

申请号：US17306424

申请日：2021-05-03

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Bhaskar Bora ,  Jeffrey Wilson ,  Michael Ferrari ,  William Stronge ,  Sandeep Chandrashekhara

IPC: G06F3/06

Abstract: A target-less point in time image (snapshot) of a storage volume is allowed to be built after activation, by enabling the snapshot data to be modified to create a crash-consistent replica of the source data after the snapshot has been activated. The data of the snapshot remains immutable from a user standpoint, but the snapshot is able to be quickly activated before all of the data of the snapshot has been included in the snapshot, to thus reduce an amount of time IO operations on the source volume are quiesced. A first snapshot of a storage volume is created on a primary storage system and a corresponding second snapshot of the storage volume is activated on a backup storage system before all the data of the first snapshot is received at the backup storage system. Entries of the activated second snapshot are then changed to point to correct back-end allocations.

公开(公告)号：US20200326878A1

公开(公告)日：2020-10-15

申请号：US16384859

申请日：2019-04-15

Applicant: EMC IP Holding Company LLC

Inventor： Bhaskar Bora ,  Richard C. Goodwill ,  Toufic Tannous

IPC: G06F3/06

Abstract: Architectures and techniques are described that can address challenges associated with engaging a procedure that has the potential to produce beneficial effects in some case and detrimental effects in other cases. One example can be engaging an early IO (EIO) protocol in a synchronous remote data facility (SRDF), but only when doing so will have a positive impact on performance and/or response times.

公开(公告)号：US20200241755A1

公开(公告)日：2020-07-30

申请号：US16260668

申请日：2019-01-29

Applicant: EMC IP Holding Company LLC

Inventor： Bhaskar Bora

IPC: G06F3/06 ,  G06F16/27 ,  H04L29/08

Abstract: Techniques for determining replication modes may include: issuing, while unsolicited data transfer mode is enabled for a first link, first write operations over the first link; issuing, while unsolicited data transfer mode is disabled for the first link, second write operations over the first link; determining a first performance metric for the first link in accordance with the first write operations; determining a second performance metric for the first link in accordance with the second write operations; and determining, in accordance with the first and second performance metrics whether to enable or disable unsolicited data transfer mode for the first link for a first time period. The first and second performance metrics may be response times. Unsolicited data transfer mode, when enabled, allows write data payload to be sent to a target without receiving an acknowledgement regarding receipt of a write command block for the write operation from the target.

公开(公告)号：US09880758B1

公开(公告)日：2018-01-30

申请号：US14672652

申请日：2015-03-30

Applicant: EMC IP Holding Company LLC

Inventor： Bhaskar Bora ,  Benjamin Yoder

IPC: G06F12/00 ,  G06F3/06

CPC classification number: G06F3/0619 ,  G06F3/061 ,  G06F3/065 ,  G06F3/0665 ,  G06F3/0689 ,  G06F2003/0692

Abstract: Described are data replication techniques. Writes of cycle N directed to a first storage device of a first data storage system are received. Writes of cycle N−1 directed to the first storage device are transmitted to a second data storage system. Writes of cycle N−2 directed to the first storage device are applied to a second storage device of the second data storage system. An acknowledgement regarding cycle N−1 is sent to the first data storage system responsive to determining that the writes of cycle N−1 directed to the first storage device have been received by the second data storage system and that the writes of cycle N−2 have been applied to the second storage device. At least some writes of cycle N directed to the first storage device are transmitted to the second data storage system prior to the first data storage system receiving the acknowledgement regarding cycle N−1.