The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 05, 2008
Filed:
Mar. 21, 2003
James Leong, Hillsborough, CA (US);
Scott Schoenthal, San Ramon, CA (US);
Srinivasan Viswanathan, Fremont, CA (US);
Rajesh Sundaram, Mountain View, CA (US);
James Leong, Hillsborough, CA (US);
Scott Schoenthal, San Ramon, CA (US);
Srinivasan Viswanathan, Fremont, CA (US);
Rajesh Sundaram, Mountain View, CA (US);
Network Appliance, Inc., Sunnyvale, CA (US);
Abstract
A technique coherently suspends input/output (I/O) operations in a RAID subsystem of a storage system. A configuration tree of the RAID subsystem has a plurality of objects representing a logical configuration of storage devices coupled to the system. According to the technique, a 'freeze' condition may be imposed on an object of the configuration tree to suspend I/O operations directed to that object. In order to freeze, I/O operations underway ('in flight') in the RAID subsystem and directed to the object need to complete sufficiently so as to reach a recoverable state in the event the subsystem subsequently fails prior to an I/O restart procedure. Once a freeze condition has been imposed, new I/O requests directed to the object are inserted onto a freeze list of pending requests at the RAID subsystem and are blocked from processing until the object is “unfrozen” (i.e., the freeze condition is lifted).