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:
Oct. 21, 2003
Filed:
Jul. 13, 2000
Benedict Michael Rafanello, Round Rock, TX (US);
Mark A. Peloquin, Austin, TX (US);
Cuong Huu Tran, Austin, TX (US);
Cristi Nesbitt Ullmann, Austin, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system and method for a multi-layer logical volume management (“LVM”) system which extends the single-layer logical volume model of current technology to handle multiple levels of aggregation more efficiently. Multiple levels of aggregation allows multiple types of aggregators, such as drive linking, mirroring, and software RAID, to be used together to bypass the limitations inherent in each individual aggregation technology. An LVM data area which stores information about the organization of the multi-layer logical volume is stored within the last partition of the logical volume. A fake EBR, which describes the logical volume as if it were a single disk drive, is located in the LVM data area of one of the partitions in the logical volume. A “bottom-to-top” control methodology is used to locate the LVM data area containing the fake EBR, including setting a special flag in the LVM data area containing the fake EBR. Aggregators search for this flag when creating aggregates, and set a flag in the LVM data area of the aggregate being created if any of the items being aggregated has this flag set. Thus, a path is built from the topmost aggregate to the partition containing the fake EBR. This path allows I/O requests to the EBR to be intercepted and easily redirected to the fake EBR, thereby improving the efficiency with which this is executed in comparison to previous methods.