Netapp, Inc.

Network Appliance, Inc.

Other

Netwrok Appliance, Inc.

Andy Kahn

John K Edwards

Kayuri Hasmukh Patel

Raymond C Chen

Edward Ramon Zayas

John F Gillono

Thomas Haynes

Emily Eng

Vignesh Sukumar

David A Grunwald

Blake H Lewis

Rajesh Sundaram

Eric C Hamilton

Srinivasan Viswanathan

Yong Cho

Himanshu Aggarwal

Sreelatha Sunkara Reddy

Maya Palem

Steven Robert Kleiman

Nitin Muppalaneni

George Cabrera, Iii

A network storage server includes a tool for detecting and fixing errors while the network storage server remains online (available for servicing client requests), which includes enabling a user to approve or disapprove remedial changes before the changes are committed. The technique bypasses the usual consistency point process for new or modified data blocks representing potential remedial changes. At a consistency point, dirty data blocks representing the potential remedial changes are written to a change log file residing outside the volume. The modified data blocks are written in sequential order to logical blocks of the change log file. In response to a user input indicating that a potential change should be committed, the corresponding modified data blocks are read from the change log file in the order in which they were written to the change log file, and they are written to persistent storage in that order.

Online data consistency checking in a network storage system with optional committal of remedial changes

A system and method verifies and restores the consistency of inode to pathname mappings. In a first embodiment, an off-line verification procedure is modified to verify and correct the primary name inode to pathname mapping information within inodes of a file system. In a second embodiment, an on-line file system verification process is modified to verify inode to pathname mapping information upon the loading of each inode within the file system.

System and method for verifying and restoring the consistency of inode to pathname mappings in a filesystem

An on-disk storage arrangement increases the number of persistent consistency point images (PCPIs) that may be maintained for a volume of a storage system. The on-disk storage arrangement comprises a novel volume information (volinfo) block representing a root of the volume; the volinfo block is stored at predefined locations on disk and comprises various system wide configuration data. The volinfo block further comprises a data structure configured to provide a level of indirection that increases the number of PCPIs maintainable by a file system executing on the storage system. To that end, the data structure may be organized as an array of pointers, wherein each pointer references a block containing a snapshot root, thereby enabling efficient access to each PCPI maintained by the file system.

Technique for increasing the number of persistent consistency point images in a file system

A system and method maintains mappings from data containers to their parent directories within a file system of a storage system. Each inode is modified to include a primary name data structure comprising a parent directory inode and a parent directory cookie value. The parent directory cookie value identifies a particular directory entry within a specified block of a directory identified by parent directory inode. An alternate name file is utilized to store alternate names, such as those associated with hard links.

System and method for maintaining mappings from data containers to their parent directories

This disclosure presents checking file system consistency for a storage server. During a start up phase of a file system, a consistency checker, upon receiving a request from an internal client for a part of data managed by a file system of the storage server, checks file system consistency only for a part of metadata. The part of metadata is used to maintain consistency of the requested data. After the consistency check of the part of metadata is completed, the internal client is allowed to access the requested data before a remainder of the metadata is checked for consistency.

File system consistency check system

A storage system, such as a file server, creates persistent consistency point images (PCPI) or 'snapshots' that are point-in-time representations of the storage system. The storage system uses persistent consistency point images to backup or mirror data. Using data already found in the data block maps associated with these PCPI, the rate of change of data between persistent consistency point images can be determined.

Rate of change of data using on-the-fly accounting

A storage system, such as a file server, creates persistent consistency point images (PCPI) or 'snapshots' that are point-in-time representations of the storage system. The storage system uses persistent consistency point images to backup or mirror data. Using data already found in the data block maps associated with these PCPI, the amount of space used by a set of these consistency points can be determined.

Method and system for determining reclaimable space occupied by a set of snapshots

The present invention relates to a system for restoring a file from a snapshot, where a version of the file exists in both an active file system and the snapshot. A twin inode is created in the active file system and comparisons are made between block pointers of the twin inode and the snapshot. If there is a match, the block pointer of the twin inode is moved to the active file system. If there is not a match, a determination is made whether the snapshot block pointer exists in the active file system. If the snapshot block pointer does not exist in the active file system, it is copied to the active file system. If it does exist, then the actual data block pointed to by the snapshot block pointer is copied to the active file system. In this way, a file may be restored without the need to always copy every individual data block or inode from the snapshot.

System and method for restoring and reconciling a single file from an active file system and a snapshot

A system and method are provided to recover lost flexible volumes of an aggregate capable of supporting flexible volumes. The method includes discovering lost flexible volumes of the aggregate and recovering them. Wherein recovering a lost flexible volume includes creating and populating a new label file associated with an container inode.

Method and system for recovering lost data volumes

A system and method are provided to check consistency of an aggregate capable of supporting flexible volumes. The method includes identifying an inode having a flexible volume type present in the aggregate; determining whether the inode is identified in a metadata directory of the aggregate; and performing consistency check on the flexible volume associated with the inode.

Method and apparatus for offline and online consistency checking of aggregates and flexible volumes

A system and method automatically generates a root volume for use by a storage operating system of a storage system. During initialization of the storage system, the storage operating system detects that no operational root volume exists and, in response, invokes a root volume generation process. The root volume generation process automatically creates a thinly provisioned flexible volume of the smallest allowable size on an aggregate. The created flexible volume is marked as the root volume for the storage system. The storage operating system then continues initialization utilizing the automatically generated root volume.

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San Francisco, CA, United States of America

Andy Kahn