Marc M Eshel

6826570, Nov 30, 2004

Jul 18, 2000

09/618371

Marc M. Eshel - San Jose CA
Carol D. Hartman - San Jose CA
Frank B. Schmuck - Campbell CA
James C. Wyllie - Monte Screno CA

International Business Machines Corporation - Armonk NY

G06F 1730

707 8, 707 10, 707200, 711152

Concurrent access to data is managed through concurrency control techniques. Various types of techniques are employed to manage the access, including locking-based techniques and non-locking-based techniques. A dynamic switch from one type of concurrency control technique (e. g. , a locking-based technique) to a different type of concurrency control technique (e. g. , a non-locking-based technique) is enabled. This switching is based on access patterns and/or application requirements for each file. The switching allows enhanced performance for both coarse-grain sharing and fine-grain sharing of data.

6959310, Oct 25, 2005

Feb 15, 2002

10/077320

Marc M. Eshel - San Jose CA, US
Roger L. Haskin - Morgan Hill CA, US
Wayne A. Sawdon - San Jose CA, US
Frank B. Schmuck - Campbell CA, US

International Business Machines Corporation - Armonk NY

G06F017/30

707200, 707 1, 707205, 709203

A system, method and computer readable medium for providing a standby file system with snapshot feature is disclosed. A first snapshot of a primary file system is generated. Next, a standby file system restores the first snapshot of the primary file system in the standby file system and a snapshot of the standby file system is taken. Then, a second snapshot of the primary file system is taken and a data set capturing the differences between the first snapshot of the primary file system and a previous data set of the primary file system is generated. Subsequently, the data set is applied to the standby file system. Upon unavailability of the primary file system, the standby file system is initialized as the new primary file system. Upon recovery of the old primary file system, the old primary file system is initialized as a new standby file system.

7085815, Aug 1, 2006

Jul 17, 2001

09/907423

Brian P. Dixon - Austin TX, US
Marc M. Eshel - San Jose CA, US
Frank B. Schmuck - Campbell CA, US

International Business Machines Corporation - Armonk NY

G06F 15/167
G06F 15/173
G06F 7/00
G06F 12/00

709213, 709214, 709225, 707 8, 711147

The amount of memory being utilized to store token state information is monitored. In response to the monitoring, one or more actions are taken. For instance, if the monitoring indicates that too much memory is being used to store token state information, then one or more actions are performed to reclaim memory and/or obtain additional memory elsewhere. These actions may include informing one or more clients to reduce their cache sizes, thereby relinquishing tokens; reducing or eliminating one or more byte range token trees; and/or migrating the token server from one node to another node. If the monitoring indicates that additional memory can be used for storing token state information, then one or more client nodes are informed that their cache sizes can be increased.

7325064, Jan 29, 2008

Jul 17, 2001

09/907119

Marc M Eshel - San Jose CA, US
Frank B Schmuck - Campbell CA, US

International Business Machines Corporation - Armonk NY

G06F 15/16

709229, 709226

Asynchronous messages are used to prefetch and/or relinquish tokens used in providing locking of shared resources. A message is sent to prefetch one or more tokens, and prior to receiving a reply for the message, another message (e. g. , an acquire) is sent for at least one of those tokens. Similarly, a message is sent indicating a voluntary relinquish of one or more tokens and without having acknowledgment that the relinquish request was processed, a further message (e. g. , an acquire) is sent for at least one of the tokens. Multiple tokens may be acquired and/or relinquished in a single message to the token server. This reduces message delays and overall message traffic.

7792980, Sep 7, 2010

Dec 20, 2007

11/961090

Marc M. Eshel - San Jose CA, US
Frank B. Schmuck - Campbell CA, US

International Business Machines Corporation - Armonk NY

G06F 15/16

709229, 709226

Asynchronous messages are used to prefetch and/or relinquish tokens used in providing locking of shared resources. A message is sent to prefetch one or more tokens, and prior to receiving a reply for the message, another message (e. g. , an acquire) is sent for at least one of those tokens. Similarly, a message is sent indicating a voluntary relinquish of one or more tokens and without having acknowledgment that the relinquish request was processed, a further message (e. g. , an acquire) is sent for at least one of the tokens. Multiple tokens may be acquired and/or relinquished in a single message to the token server. This reduces message delays and overall message traffic.

7962915, Jun 14, 2011

Mar 18, 2005

11/084446

Marc M. Eshel - San Jose CA, US
Juan Carlos Gomez - San Jose CA, US
Manoj Premanand Naik - San Jose CA, US

International Business Machines Corporation - Armonk NY

G06F 9/46
G06F 11/00

718105, 714 2

A state management system preserves a state for a cluster of file servers in a cluster file system in the presence of load balancing, failover, and fail-back events. The system provides a file and record locking solution for a clustered network attached storage system running on top of a cluster file system. The system employs a lock ownership scheme in which ownership identifiers are guaranteed to be unique across clustered servers and across various protocols the clustered servers may be exporting. The system supports multi-protocol clustered NAS gateways, NAS gateway server failover and fail-back, and load-balancing architectures. The system further eliminates a need for a lock migration protocol, resulting in improved efficiency and simplicity.

8458239, Jun 4, 2013

Dec 16, 2009

12/639904

Rajagopol Ananthanarayanan - San Jose CA, US
Marc M. Eshel - San Jose CA, US
Roger L. Haskin - Morgan Hill CA, US
Dean Hildebrand - San Jose CA, US
Manoj P. Naik - San Jose CA, US
Frank B. Schmuck - Campbell CA, US
Renu Tewari - San Jose CA, US

International Business Machines Corporation - Armonk NY

G06F 17/30

707828, 707827, 707737, 711118

Directory traversal in a scalable multi-node file system cache for a remote cluster file system, is provided. One implementation involves maintaining a scalable multi-node file system cache in a local cluster file system, and caching local file data in the cache by fetching file data on demand from a remote cluster file system into the cache over the network. The local file data corresponds to file data in the remote cluster file system. The local namespace emulates the remote namespace and is created on demand. Access to data further involves performing directory traversal for the cache for the remote cluster file system by creating a directory structure on demand.

8473582, Jun 25, 2013

Dec 16, 2009

12/639920

Rajagopol Ananthanarayanan - San Jose CA, US
Marc M. Eshel - San Jose CA, US
Roger L. Haskin - Morgan Hill CA, US
Dean Hildebrand - San Jose CA, US
Manoj P. Naik - San Jose CA, US
Frank B. Schmuck - Campbell CA, US
Renu Tewari - San Jose CA, US

International Business Machines Corporation - Armonk NY

G06F 15/16

709218, 709248, 709224, 709223, 709212

Facilitating access to data in a network, is provided. One implementation involves maintaining a scalable multi-node file system cache in a local cluster file system, and caching file data in a cache by fetching file data on demand from a remote cluster file system into the local cached file system over the network. The local file data corresponds to file data in the remote cluster file system. Upon disconnection from the remote cluster file system, all file operations are supported at the cache. Then, upon reconnection to the remote cluster file system over the network, the remote cluster file system is synchronized with the information cached in the cache during the disconnection even in the presence of failures.