Methods and apparatus for backup and restoring systems
AssigneeHitachi, Ltd.
InventorKenji Yamagami
Life of this patent
Estimating the term…
Abstract
The present invention provides techniques for managing storage based replication. Specific embodiments provide techniques for performing system backup and restoring. In specific embodiments, benefits such as keeping a remote mirror between a primary volume and a secondary volume in operation can be provided. Since the remote mirror is usually used for disaster recovery purposes, where the mirrors must be always in-sync state, being able to take a backup without breaking the remote mirror can help provide a constant duplicate copy of production information in case of emergency, for example. Further, in some embodiments, a user can take backups of more than one generation by setting up two or more secondary volumes (SVOLs) for one primary volume (PVOL).
Claims20
A method of backup and restore procedure using a first storage subsystem and second storage subsystem which are connected to each other via a path, the first storage subsystem connected to a first host, the second storage subsystem connected to a second host, the method comprising the steps of:
- performing a backup procedure comprising the steps of:
- providing a first logical volume to the first storage subsystem and a second logical volume and a third logical volume in the second storage subsystem, the second logical volume being a copied logical volume of the first logical volume, the first and second logical volumes being in sync state, the third logical volume being a copied logical volume of the second logical volume, the second and third logical volumes being in sync state;
- and
- splitting the second logical volume and the third logical volume from the first host by a command from the first storage subsystem;
- and
- performing a restore procedure comprising the steps of:
- mounting the third logical volume to the second host,
- reading, at the second host, a file to be restored from the third volume,
- writing, at the second host, the file to the second volume, and
- re-synchronizing the first volume with the second volume.
A method, comprising:
- receiving an indication of files to be restored;
- determining whether the files to be restored comprise contents of an entire volume, and if so:
- splitting remote mirrors existing between the production volumes and backup volumes;
- resynchronizing local mirrors existing between the backup volumes and volumes holding data copied from the backup volumes;
- and
- resynchronizing remote mirrors for the production volumes and the backup volumes.
An apparatus, comprising:
- means for receiving an indication of files to be restored;
- means for determining whether the files to restore comprise contents of an entire volume;
- means for splitting remote mirrors existing between the production volumes and backup volumes;
- means for resynchronizing local mirrors existing between the backup volumes and volumes holding data copied from the backup volumes;
- and
- means for resynchronizing remote mirrors for the production volumes and the backup volumes.
A method of restoring a file to a first storage subsystem connected to a first host from a second storage subsystem connected to a second host, in accordance with a request from the first host, wherein:
- the first storage subsystem and second storage subsystem are connected each other via a path, the first storage subsystem stores a first logical volume, the second storage subsystem stores a second logical volume and a third logical volume, the second logical volume being a copied logical volume of the first logical volume, the third logical volume being a copied logical volume of the second logical volume, the first logical volume and the second logical volume being in a non-sync state, the second and third logical volumes being in sync state,
- the method comprising:
- mounting the third logical volume to the second host,
- reading, at the second host, a file to be restored from the third volume and
- writing, at the second host, the file to the second volume, and
- re-synchronizing the first volume with the second volume.
A storage subsystem, comprising:
- a first logical volume,
- a second logical volume, and
- an interface to a path providing connectivity to a primary storage subsystem,
- the second logical volume being a copied logical volume of the first logical volume,
- the first logical volume operative to be selectively placed into one of a sync state and a non-sync state with a logical volume in a primary storage subsystem,
- the first logical volume and second logical volume being in sync state,
- the second logical volume operative to permit host access to read files to be restored from the second logical volume and write the files to be restored to the first logical volume responsive to a restore command, and
- the second storage subsystem operative to establish a sync state between the first logical volume and the second logical volume.
A computer program product, comprising:
- code for receiving an indication of files to be restored;
- code for determining whether the files to be restored comprise contents of an entire volume, and if so invoking a plurality of codes, comprising:
- code for splitting remote mirrors existing between the production volumes and backup volumes;
- code for resynchronizing local mirrors existing between the backup volumes and volumes holding data copied from the backup volumes;
- code for resynchronizing remote mirrors for the production volumes and the backup volumes;
- and
- a computer readable storage medium that holds the codes.
An apparatus, comprising:
- means for receiving a command;
- means for splitting a sync state existing between a second storage means and a third storage means;
- means for making information on the third storage means available for reading;
- means for reading a file to be restored from the third storage means;
- means for writing the file to the second storage means;
- and
- means for re-synchronizing the second storage means with a first storage means.
A computer program product, comprising:
- code for receiving a command;
- code for splitting a sync state existing between a second storage unit and a third storage unit;
- code for making information on the third storage unit available for reading;
- code for reading a file to be restored from the third storage unit;
- code for writing the file to the second storage unit;
- code for re-synchronizing the second storage unit with a first storage unit;
- and
- a computer program product that holds the codes.
A system, comprising:
- a first storage subsystem connected to a first host,
- a second storage subsystem connected to a second host, wherein:
- the first storage subsystem and the second storage subsystem are connected to each other via a path, the first storage subsystem stores a first logical volume, the second storage subsystem stores a second logical volume and a third logical volume, the second logical volume being a copied logical volume of the first logical volume, the third logical volume being a copied logical volume of the second logical volume, the first logical volume and the second logical volume being in a non-sync state, the second and third logical volumes being in sync state, the second storage subsystem operative to mount the third logical volume to the second host responsive to a restore command, the host operative to read files to be restored from the third volume and write the files to be restored to the second volume, and the second storage subsystem operative to establish a sync state between the first logical volume and the second logical volume.
Dependencies are inferred from the claim text.