International Business Machines Corporation

Nikhil Khandelwal

Richard Albert Welp

Gregory E McBride

David C Reed

Thomas W Bish

Joseph W Dain

Anthony J Ciaravella

Benjamin L Andrews

Aaron S Palazzolo

Benjamin S Terris

Andrew W Grimes

Matthew Charles Compton

Michael R Maletich

Steve P Wallace

Erik Rueger

Robert Beverley Basham

Thorsten Muehge

Stefan Lehmann

Michael Diederich

Ricardo Sedillos Padilla

Kerri Renee Shotwell

Thomas Holderness Daily

Michael M Latif, Iv

Jason A Ogroski

Provided are a computer program product, system, and method for selective write control in accordance with the present description. In one aspect, a write operation which is associated with a read operation, may be selectively discarded if write operations have been disabled and if the write operation is directed to update a designated write operation acceptance area such as metadata associated with the target data set, for example. As a result, the read operation may be permitted to proceed and will not fail because the associated write operation was discarded rather than attempting to commit the write operation to the designated write operation acceptance area, thereby avoiding an error condition for a storage unit such as a volume, in which write operations have been disabled. Accordingly, applications which seek to perform read operations may be permitted to access data stored on such a volume. Other aspects are described.

Selective write control

A mechanism is provided in a data processing system for managing filesystem inodes. The mechanism monitors inode consumption in a filesystem. The mechanism periodically determines a number of inodes to add to the filesystem based on the inode consumption and adds the number of inodes to the filesystem.

Managing filesystem inodes

A computer-implemented method, according to one embodiment, includes: determining, using a processor, whether a virtual machine is authorized to run using a data structure having metadata about properties of the virtual machine; determining, using the processor, whether a hypervisor is authorized to run the virtual machine using a digital signature of the data structure; and running the virtual machine on a computer system using the hypervisor in response to determining that the virtual machine is authorized to be run and that the hypervisor is authorized to run the virtual machine. Other systems, methods, and computer program products are described in additional embodiments.

Hypervisor and virtual machine protection

An apparatus for providing traffic alerts includes a distance module, analysis module, transmission module, and signaling module. The distance module measures the distance between a vehicle and an object in front of the vehicle. The analysis decides whether to signal a presence of the object that comprises determining that the measured distance is equal to or less than a threshold distance. The transmission module transmits an alert in response to the analysis module deciding to signal a presence of the object. The signaling module transmits a visual signal to one or more vehicles behind the vehicle in response to receiving the alert from the transmission module. The visual signal has one or more characteristics.

Traffic safety alert system

Disclosed aspects include management of a set of blocks in a storage system. A set of write requests is initiated to the set of blocks. In response to the set of write requests, a set of expiration metadata for the set of blocks is established. Based on the set of expiration metadata, an expiration event is detected. In response to detecting the expiration event, an expiration operation on the set of blocks is processed.

Managing a set of blocks in a storage system

A computer-implemented method, according to one embodiment, includes receiving a request for a hypervisor to run a virtual machine; determining, using a processor, whether the virtual machine is authorized to run using a data structure having metadata about properties of the virtual machine; determining, using the processor, whether the hypervisor is authorized to run the virtual machine using a digital signature of the data structure; and running the virtual machine on a computer system using the hypervisor in response to determining that the virtual machine is authorized to be run and that the hypervisor is authorized to run the virtual machine. Other systems, methods, and computer program products are described in additional embodiments.

Various method, system, and computer program product embodiments for facilitating upgrades in a computing storage environment are provided. In one such embodiment, one of an available plurality of rolling upgrade policies is defined by specifying the at least one selectable upgrade parameter, including specifying one of a commencement time and duration of an upgrade procedure. A node down tolerance factor is set for at least one node in the computing storage environment. A determination of whether a number of at least one of a plurality of nodes in the computing storage environment currently down, including a target node to be upgraded, does not exceed the node down tolerance factor, and if the node down tolerance factor is not exceeded, a cluster health is checked.

Intelligent rolling upgrade for data storage systems

A method for defragmenting volumes in a mirrored system. The method includes determining that a defragmentation process has been performed on a second server. The method further includes storing a before and after mapping of a second set of tracks, wherein the before and after mapping includes information identifying at least one track of the second set of tracks and a corresponding first location of the respective track before the performing of the defragmentation process and a second location of the respective track after the performing of the defragmentation process and sending an indication to a first server to relocate at least one track of a first set of tracks on the first server from a first location on the first server to a second location on the first server according to the stored before and after mapping of the corresponding second set of tracks on the second server.

Shifting a defrag operation in a mirrored system

A computer system for defragmenting volumes in a mirrored system is provided. The computer system includes program instructions for suspending one or more updates from being mirrored from a first set of tracks on a first server to a second set of tracks on a second server. A defragmenting process is performed on the second server. The defragmentation process stores a before and after mapping of the second set of tracks, wherein the before and after mapping includes information identifying at least one track of the second set of tracks and a corresponding first location of the respective track before the defragmenting and a second location of the respective track after the defragmenting. The computer system further includes program instructions for, upon defragmenting, relocating at least one track of the first set of tracks on the first server according to the stored before and after mapping.

A computer program product for defragmenting volumes in a mirrored system is provided. The computer program product includes program instructions for suspending one or more updates from being mirrored from a first set of tracks on a first server to a second set of tracks on a second server. A defragmenting process is performed on the second server. The defragmentation process stores a before and after mapping of the second set of tracks, wherein the before and after mapping includes information identifying at least one track of the second set of tracks and a corresponding first location of the respective track before the defragmenting and a second location of the respective track after the defragmenting. The computer program product further includes program instructions for, upon defragmenting, relocating at least one track of the first set of tracks on the first server according to the stored before and after mapping.

A method for releasing storage space in a space-efficient volume is disclosed. In one embodiment, such a method includes maintaining, for a space-efficient volume, a bitmap comprising a bit for each track in the space-efficient volume. A host system indicates whether a track is one of used and unused by marking the corresponding bit in the bitmap. A storage controller reads the bitmap and frees tracks from the space-efficient volume that the bitmap indicates are unused. In certain embodiments, the bitmap is stored on the space-efficient volume. For example, the bitmap may be appended to a volume table of contents (VTOC) stored on the space-efficient volume. A corresponding system and computer program product are also disclosed.

Growing community of inventors

Tucson, AZ, United States of America

Nikhil Khandelwal