International Business Machines Corporation

David Luciani

Erika Dawson

Ralph Thomas Beeston

Joel Kenneth Lyman

Duke Andy Lee

Raymond Anthony James

William Henry Travis

Joseph W Dain

James Arthur Fisher

Jyoti K Shah

A method according to one embodiment includes outputting a first alert when a cache free space size is less than a first threshold and entering into a warning state, and outputting a second alert when the cache free space size is less than a second threshold and entering into a critical state. At least one scratch volume is deleted when in the critical state, the scratch volume chosen based on at least one of: a length of time the scratch volume has been designated scratch, a priority level of the information stored on the scratch volume, and a scratch delay value associated with the scratch volume.

Managing a cache in a multi-node virtual tape controller

According to one embodiment, a system includes a virtual tape library having a cache, a virtual tape controller (VTC) coupled to the virtual tape library, and an interface for coupling multiple hosts to the VTC. The cache is shared by the multiple hosts, and a common view of a cache state, a virtual library state, and a number of write requests pending is provided to the hosts by the VTC. In another embodiment, a method includes receiving data from at least one host using a VTC, storing data received from all the hosts to a cache using the VTC, sending an alert to all the hosts when free space is low and entering into a warning state, sending another alert to all the hosts when free space is critically low and entering into a critical state while allowing previously mounted virtual drives to continue normally.

According to one embodiment, a method for managing cache space in a virtual tape controller includes receiving data from at least one host using the virtual tape controller; storing data received from the at least one host to a cache using the virtual tape controller; sending a first alert to the at least one host when a cache free space size is less than a first threshold and entering into a warning state using the virtual tape controller; sending a second alert to the at least one host when the cache free space size is less than a second threshold and entering into a critical state using the virtual tape controller; and allowing previously mounted virtual drives to continue normal writing activity when in the critical state.

Methods for managing a cache in a multi-node virtual tape controller

According to one embodiment, a system includes a virtual tape library having a cache, a virtual tape controller (VTC) coupled to the virtual tape library, and an interface for coupling at least one host to the VTC. The cache is shared by all the hosts, and a common view of a cache state, a virtual library state, and a number of write requests pending is provided to all the hosts by the VTC.

Systems for managing a cache in a multi-node virtual tape controller

An apparatus, system, and method are disclosed for interfacing a driver with an encryption source that uses a communication module that allows the driver and the encryption source to communicate messages to one another, wherein the messages result in the encryption source providing encryption data that the communication module relays to the driver.

Apparatus, system, and method for communication between a driver and an encryption source

An apparatus, system, and method are disclosed for automatically and transparently mapping tape drives within tape libraries to IP addresses. In one embodiment, the tape library includes, a DHCP server, a LAN to serial switch, and a library manager configured with the necessary modules to map the tape library devices to the proper IP addresses. The entire process may be transparent to users. The result is that the tape library is configured with the proper IP addressing without costly, time-consuming, and error-prone manual intervention. The tape library can be configured more quickly with accurate IP addressing and is able to operate efficiently and properly.

Apparatus, system, and method for automatically mapping a tape library system

A system and method for efficiently and accurately detecting errors in a network is provided. Devices coupled to a network are configured to determine their local network status and transmit their local network status to a centralized location. The centralized location is configured to receive the local network status from each device and provide network status for the entire network. The centralized location is also configured to analyze the collective network status information and report any network errors. The centralized location is further configured to present the information in a format that allows a user of the network to quickly determine the configuration and status of the network (such as a computer generated graphical representation of the network).

System and method for detecting errors in a network

A method for peer-to-peer system recovery, where the peer-to-peer system comprises a plurality of virtual tape controllers in communication with a first virtual tape server and with a second virtual tape server. The method generates a shutdown key, saves that shutdown key in each of the plurality of virtual tape controllers, and takes both virtual tape servers out of operation. Subsequently, the method returns one of the virtual tape servers to operation. Each virtual tape controller decides whether to place that operational virtual tape server on-line, and determines if the number of virtual tape controllers electing to place the operational virtual tape server on-line is greater than a pre-determined VTC agreement threshold. If the number of virtual tape controllers electing to place the operational virtual tape server on-line is greater than the VTC agreement threshold, then the method places the peer-to-peer system on-line using only the operational virtual tape server.

Growing community of inventors

Tucson, AZ, United States of America

David Luciani