公开(公告)号：US20200334111A1

公开(公告)日：2020-10-22

申请号：US16385270

申请日：2019-04-16

Applicant: EMC IP Holding Company LLC

Inventor： Ajay Potnis ,  Adnan Sahin ,  Kiran B. Halwai

IPC: G06F11/14 ,  G06F16/11

Abstract: Techniques for performing a restoration may include: creating a first snapshot of a primary file system at a first point in time; and at a second point in time, performing first processing to restore at least a portion of the primary file system from the first point in time. The first processing may include: creating a second snapshot of the first snapshot of the primary file system; exporting the second snapshot as a first target device; mounting the first target device as a read-write checkpoint file system; performing file system consistency processing on the read-write checkpoint file system; and subsequent to performing the file system consistency processing on the read-write checkpoint file system, restoring at least a portion of the primary file system from the second snapshot using the read-write checkpoint file system. The file system consistency processing may include correcting metadata inconsistencies of the read-write checkpoint file system.

公开(公告)号：US11467929B2

公开(公告)日：2022-10-11

申请号：US16561073

申请日：2019-09-05

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Amit Dharmadhikari ,  Adnan Sahin ,  Ajay Potnis

IPC: G06F11/20 ,  G06F11/30 ,  G06F3/06

Abstract: A storage node that maintains a replica of a logical volume for use in response to a failover trigger includes a data node with volatile memory in which a filesystem and its metadata and a VDM and its metadata associated with the replica are maintained prior to the failover trigger. The storage node also includes a SAN node in which data associated with the replica is maintained. The data is maintained in a RW (read-write) state by the SAN node prior to the failover trigger. However, the replica is presented in a RO (read-only) state by the storage node prior to the failover trigger. The storage node changes the in-memory state of the filesystem and VDM to RW responsive to the failover trigger. Because the filesystem and its metadata and VDM and its metadata are already in memory and the data is in a RW state in block storage the failover is completed relatively quickly.

公开(公告)号：US11068502B1

公开(公告)日：2021-07-20

申请号：US16176060

申请日：2018-10-31

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Ajay Potnis ,  Adnan Sahin ,  Michael Specht ,  Bharadwaj Sathavalli ,  Shampavman Chenjeri Gururajarao ,  Maneesh Singhal

IPC: G06F16/30 ,  G06F16/27 ,  G06F3/06

Abstract: Software Defined Network Attached Storage data backup is implemented using storage array synchronous data replication. A TLU is created for each user filesystem managed by a Virtual Data Mover (VDM). A VDM configuration filesystem is also created containing metadata describing a mapping of user file system TLU to physical storage resources on the storage array. Both the user filesystem TLUs and the VDM configuration filesystem are mapped to an asynchronous Remote Data Forwarding (RDF) group of the storage array, which is used by the storage array to replicate both the user filesystem TLUs and VDM configuration filesystem. Filesystem ID and export path information are reserved on the primary storage array and backup storage array when the RDF group is set up, to enable transparent failover from the primary to the backup node of selected VDMs.

公开(公告)号：US20210073088A1

公开(公告)日：2021-03-11

申请号：US16561073

申请日：2019-09-05

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Amit Dharmadhikari ,  Adnan Sahin ,  Ajay Potnis

IPC: G06F11/20 ,  G06F11/30 ,  G06F3/06

Abstract: A storage node that maintains a replica of a logical volume for use in response to a failover trigger includes a data node with volatile memory in which a filesystem and its metadata and a VDM and its metadata associated with the replica are maintained prior to the failover trigger. The storage node also includes a SAN node in which data associated with the replica is maintained. The data is maintained in a RW (read-write) state by the SAN node prior to the failover trigger. However, the replica is presented in a RO (read-only) state by the storage node prior to the failover trigger. The storage node changes the in-memory state of the filesystem and VDM to RW responsive to the failover trigger. Because the filesystem and its metadata and VDM and its metadata are already in memory and the data is in a RW state in block storage the failover is completed relatively quickly.

公开(公告)号：US20200379849A1

公开(公告)日：2020-12-03

申请号：US16427402

申请日：2019-05-31

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Ajay Potnis ,  Amit Dharmadhikari

IPC: G06F11/14 ,  G06F16/11 ,  G06F16/182 ,  H04L29/08 ,  H04L12/24

Abstract: Snaps are distributed among data nodes for load balancing and overload avoidance. A snap is initially associated with a first VNAS server on a first data node that hosts the primary volume being snapped. A second data node is selected based on loading. The second data node may be in the same or a different cluster. A second VNAS server is instantiated on the second data node. The snap is then mounted on the second VNAS server. The second VNAS server may be configured as the target for all reads to the snap. If the second data node is in a different cluster than the snap may be copied or moved from a first SAN node to a second SAN node. Multiple copies of snaps may be distributed, and individual snaps and copies may be associated with different SLOs.