Abstract:
The present invention relates to a method for byzantine fault tolerant data replication with a plurality of 2f+1 data servers and one or more clients, wherein data is stored in at least f+1 different data servers out of the 2f+1 data servers and wherein metadata of the stored data is stored under a metadata-identifier in a fault-tolerant metadata-service, wherein the metadata to be stored includes a unique identifier of the stored data, a fingerprint of the stored data and a list of data servers which have stored the data. The present invention further relates to a system for byzantine fault tolerant data replication.
Abstract:
Aspects of the subject matter described herein relate to data protection of files that may include both content and embedded metadata. In aspects, an indication that a file has changed is received. If the content has changed, the entire file or just the content may be backed up. If the metadata only has changed, the metadata may or may not be backed up, depending on implementation. Instead of parsing the file to determine the exact size and positioning of the metadata within the file, the file may be divided into three portions: a head portion, a middle portion, and a tail portion. Hashes of these portions may then be used to determine whether the metadata and/or content of the file have changed.
Abstract:
A file server system tolerant to hardware and software failures is located over a plurality of hardware nodes. The nodes of the system act as hosts for software components of the system. Several of the software components can be replicated. The replicable software components include the system file store, a checker and a logger. The replicated components have one primary copy and one or more back-up copies. Replica copies of a given replicated component are each located at different nodes. Location and handling of replica copies of a given replicable component is under the control of a replication manager which is a (non-replicable) software component of the system. The replication manager is distributed meaning it can have one of its instances running on each node of the system. These instances intercommunicate to maintain coherence. The failure detector is also distributed, its instances running on each of the nodes, and contributing to an early detection of hardware and software failures. The file store is configured to hold stored objects and includes a signature generator for computing an object-specific signature from an object. The checker comprises a signature store for holding a previously computed signature for each of the stored objects and a comparator operable to compare a signature retrieved from the signature store with a corresponding signature computed by the signature generator from an object retrieved from the file store, thus to enhance system reliability.
Abstract:
A laptop computer back up logic system (300) copies user selected files or automatically selected files for back up as the laptop computer (24) is being used. Changed files are backed up and stored in a hold area of the laptop computer (24). When the laptop computer (24) senses a network connection and the network (14) is idle, the blocks of the changed files are transmitted from the hold area to a remote facility (12) via the network (14). The backing up process can be triggered within the laptop computer (24) when the screen saver of the laptop computer (24) is invoked.
Abstract:
PROBLEM TO BE SOLVED: To automatically back up user data anywhere and anytime through a wireless network without utilizing a dedicated backup device and without bringing a wireless device to a repair service counter when the wireless device has trouble, is lost or is stolen. SOLUTION: A difference engine for backup and a backup agent are mounted on a backup server and a wireless device, and user data stored in the wireless device are bucked up as necessary by a difference system into the backup server at a remote place via a wireless network. As the backup destination, a computer directly connectable to the wireless device and a memory card to be inserted into the wireless device are recommended other than the backup server installed at the remote place. The backed-up user data are restored in the same or different kinds of wireless devices as necessary. COPYRIGHT: (C)2009,JPO&INPIT
Abstract in simplified Chinese:提供一种将一虚拟机(VM)影像应用于一电脑系统之方法。在借由一信息处置系统实施之该方法中,进行在该电脑系统上运行之一当前VM影像正遭遇一问题的一侦测。作为回应,分析先前VM影像,其中该等先前VM影像中之每一者为先前在该电脑系统上运行之一影像。基于该分析,选择该等先前VM影像中之一者且使用该选定影像以替换该电脑系统上之该当前VM影像。