Abstract: The techniques introduced herein provide an efficient mechanism for reducing remote procedure requests to storage server nodes in a cluster of the storage servers to construct a directory path for a data container. According to one aspect of the invention, a new caching technique and an efficient organization of the cache memory are provided so that a cache memory on a storage server node is populated with individual path components of a directory structure. A novel cache invalidation mechanism is provided to maintain cache consistency at the cache so that when a path component changes, such as an identifier of a data container in the directory structure, and a path component is invalidated in the cache memory, the remaining path components can be retained and later reused.

Abstract: Methods and/or systems for efficiently handling a request from a client for a target component (e.g., file) stored on a remote or secondary node in a clustered storage system are provided. In response to a request from the client for the target component, a first node to which the client is locally connected retrieves a list of one or more logical interfaces (LIFs) and generates a response comprising an indication that the requested target component is not covered by this first node and a list of one or more internet protocol (IP) addresses that correspond to the retrieved LIFs for accessing the secondary node. This allows the client to connect locally to the secondary node so that the target component can be retrieved locally and thus more efficiently regardless of where (e.g., upon which node) the file is stored within the cluster.

Abstract: An image file format and a method of creating and restoring an image file is provided by the present invention. The image file format includes a plurality of streams such as a control stream, a data stream, a bitmap stream, and a cluster map stream. An audit trail stream, properties stream and fix-up stream may also be provided. The present invention allows the contents of a storage media to be captured and stored as an image file. The image file is used to restore the storage media to a previous state or allows multiple computers to be provided with a common configuration. The plurality of streams further allow the image file to be viewed, edited or otherwise manipulated.

Abstract: A system and method for probing a plurality of clients for a rate appropriate for multicasting is described. In one implementation, test data is sent by a server to a plurality of clients. A rate, Ri, based at least in part on a rate at which test data was received, is sent by at least some of the plurality of clients to the server. A rate, R0, at which an image is to be sent to the plurality of clients, is then calculated as a function of at least some of the Ri.

Abstract: An image file format and a method of creating and restoring an image file is provided by the present invention. The image file format includes a plurality of streams such as a control stream, a data stream, a bitmap stream, and a cluster map stream. An audit trail stream, properties stream and fix-up stream may also be provided. The present invention allows the contents of a storage media to be captured and stored as an image file. The image file is used to restore the storage media to a previous state or allows multiple computers to be provided with a common configuration. The plurality of streams further allow the image file to be viewed, edited or otherwise manipulated.

Abstract: A method for transporting an image file over a network is provided. The network may include two or more computers, and the image file may include a control stream, a data stream, and a cluster map stream. The method may include parsing the image file into two or more segments. A first segment may include the control stream, the cluster map stream and a first portion of the data stream. A second segment includes a second portion of the data stream. The method may also include sending the first segment from a first computer to a second computer, and sending the second segment from the first computer to the second computer.

Abstract: A technique efficiently creates and serves a backup data set on a backup filer located at a remote site from a primary filer by essentially moving an entire operating environment of a primary data set to the backup filer. The primary filer is organized into one or more virtual filers (vfilers), one of which (the primary vfiler) is configured to serve data, such as the primary data set, for a client. In the event that the primary filer or primary vfiler becomes unavailable, the technique may be implemented as a disaster recovery or data migration sequence to enable efficient instantiation of a backup vfiler to serve the backup data set for the client.

Abstract: A system and method for encryption and decryption of files. The system and method operate in conjunction with the file system to transparently encrypt and decrypt files in using a public key-private key pair encryption scheme. When a user puts a file in an encrypted directory or encrypts a file, data writes to the disk for that file are encrypted with a random file encryption key generated from a random number and encrypted with the public key of a user and the public key of at least one recovery agent. The encrypted key information is stored with the file, whereby the user or a recovery agent can decrypt the file data using a private key. With a correct private key, encrypted reads are decrypted transparently by the file system and returned to the user. One or more selectable encryption and decryption algorithms may be provided via interchangeable cryptographic modules.

Abstract: A system and method for probing a plurality of clients for a rate appropriate for multicasting is described. In one implementation, test data is sent by a server to a plurality of clients. A rate, Ri, based at least in part on a rate at which test data was received, is sent by at least some of the plurality of clients to the server. A rate, R0, at which an image is to be sent to the plurality of clients, is then calculated as a function of at least some of the Ri.

Abstract: A method and system for recovering from a system failure wherein the failed system is restored to a new system that has different hardware. Hardware state is preserved during a backup process, and following a failure, a restore is performed to the extent possible using that hardware state but on a system having a different hardware configuration. Rules are provided for handling the differences through selective merging, arranging, and replacement of data, with the logic and work performed transparently to the user. Hardware state includes hard disk configuration information, the location (partition) of the operating system, devices installed on the system and any additional drivers to load. When restored, for hardware that is identical, the hardware state is restored as specified in the file. If the hardware state is not identical, then a set of rules are used to restore the hardware state.

Abstract: A system and method for encryption and decryption of files. The system and method operate in conjunction with the file system to transparently encrypt and decrypt files in using a public key-private key pair encryption scheme. When a user puts a file in an encrypted directory or encrypts a file, data writes to the disk for that file are encrypted with a random file encryption key generated from a random number and encrypted with the public key of a user and the public key of at least one recovery agent. The encrypted key information is stored with the file, whereby the user or a recovery agent can decrypt the file data using a private key. With a correct private key, encrypted reads are decrypted transparently by the file system and returned to the user. One or more selectable encryption and decryption algorithms may be provided via interchangeable cryptographic modules.