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(12) United States Patent (10) Patent No.: US 6,711,591 B1 Rafanell0 Et Al

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(12) United States Patent (10) Patent No.: US 6,711,591 B1 Rafanell0 Et Al USOO6711591B1 (12) United States Patent (10) Patent No.: US 6,711,591 B1 Rafanell0 et al. (45) Date of Patent: Mar. 23, 2004 (54) TOP-DOWN CONTROL OF MULTIPLE 5,897,661 A 4/1999 Baranovsky et al......... 711/170 LAYERAGGREGATION LOGICAL VOLUME 6,192,471 B1 2/2001 Pearce et al. .................. 713/2 MANAGEMENT DATA AND BOOT RECORD 6,366,986 B1 * 4/2002 St. Pierre et al. ........... 711/162 6,401,183 B1 6/2002 Rafizadeh ................... 711/173 (75) Inventors: Benedict Michael Rafanello, Round * cited b Rock, TX (US); Mark A. Peloquin, cited by examiner Austin, TX (US); Cuong Huu Tran, Austin, TX (US); Cristi Nesbitt Primary Examiner Jeffrey Gaffin Ullmann, Austin, TX (US) Assistant Examiner Mike Nguyen (74) Attorney, Agent, or Firm-Robert H. Frantz; David A. (73) Assignee: International Business Machines Mims, Jr. Corporation, Armonk, NY (US) (57) ABSTRACT (*) Notice: Subject to any disclaimer, the term of this A System and method for control of data and boot records patent is extended or adjusted under 35 asSociated with multi-layer logical volumes allows the logi U.S.C. 154(b) by 470 days. cal volume data area containing the fake EBR to be deter ministically and efficiently accessed by using a "top down” (21) Appl. No.: 09/616,146 control methodology. Control of the logical volume manager (“LVM') data area is distributed. An LVM data area is (22) Filed Jul. 13, 2000 placed on each aggregate as well as on each partition, and (51) Int. Cl." ................................................ G06F 1200 the fake EBR is placed in the LVM data area of the topmost (52) U.S. Cl. ....................... 707/200; 707/201: 707/202; aggregate. The topmost aggregator controls access to the 707/203; 707/204; 707/205; 707/206; 711/111; fake EBR, and only this aggregator must provide API 711/112; 711/114; 711/162; 713/1; 713/2 functionality to access the fake EBR. This allows the fake (58) Field of Search 711/161, 162 EBR to be found and accessed only by new software 711/7073 111114,713/12. 707/200206 applications which are “aware” of the fake EBR, while s s s as allowing legacy aggregators to continue to function cor (56) References Cited rectly and allowing legacy Software applications to continue to interwork with legacy aggregators through their U.S. PATENT DOCUMENTS unchanged APIs. 5,790.773. A 8/1998 DeKoning et al. ..... 395/182.04 5,796,988 A 8/1998 Naidu et al. ................ 395/500 27 Claims, 6 Drawing Sheets U.S. Patent Mar. 23, 2004 Sheet 1 of 6 US 6,711,591 B1 U.S. Patent Mar. 23, 2004 Sheet 2 of 6 US 6,711,591 B1 SZ 14VAO142|| z21/16/g U.S. Patent Mar. 23, 2004 Sheet 3 of 6 US 6,711,591 B1 s U.S. Patent Mar. 23, 2004 Sheet 4 of 6 US 6,711,591 B1 Prior Art -4 Extended Partion 3ture 4 U.S. Patent Mar. 23, 2004 Sheet 6 of 6 US 6,711,591 B1 -N- N f - N 3 f \d St Da e O \d SoulS L1 N ya \d NO S2 No. 1 N wa S. 5-NO & (5) MSS 3 Scud- S - 3SC) US 6,711591 B1 1 2 TOP-DOWN CONTROL OF MULTIPLE as the IBM OS/2 operating system provides high level LAYERAGGREGATION LOGICAL VOLUME management of the System resources, including the multi MANAGEMENT DATA AND BOOT RECORD tasking or multi-threaded Scheduling and prioritization of the System application programs (25). Drivers (23) provide CROSS-REFERENCE TO RELATED Specific high-level interface and control functions for Spe APPLICATIONS (CLAIMING BENEFIT UNDER cific hardware, Such as a manufacturer and model-specific LAN interface card driver or CD-Rewritable (“CD-RW) 35 U.S.C. 120) driver. This generalized view of the System also applies to This application is related to U.S. application Ser. No. Systems on alternate, non-IBM-compatible platforms, Such 09/561,184 filed on Apr. 27, 2000, and to U.S. application as workStations, which employ a variety of operating Sys Ser. No. 09/616,131 filed on Jul. 13, 2000, both by Benedict tems such as Microsoft Windows, UNIX or LINUX. This Michael Rafanello, et al. Both related application are com general organization of computer System resources and monly assigned. Software functionality is well understood in the art. Turning to FIG. 3, disk-based mass Storage devices Such FEDERALLY SPONSORED RESEARCH AND as hard disk drives, floppy disks and CD-ROMS are based DEVELOPMENT STATEMENT 15 physically on a rotating Storage platter (30). This platter may be made of flexible mylar, Such as floppy disks, or more rigid This invention was not developed in conjunction with any platters made of aluminum, glass or plastic, Such as hard Federally sponsored contract. disk drives and CD-ROMS. For magnetic media, one or both Sides of the platter are coated with a magnetic layer capable MICROFICHEAPPENDIX of recording magnetic pulses from a read/write head. For optical media, data recording is made using changes in Not applicable. reflectivity of a band of light, which is then read by a laser-based head. Writable and Re-writable CD-ROM drives INCORPORATION BY REFERENCE combine the technologies of magnetic disks and optical The related application, Ser. Nos. 09/561,184 and 09/616, 25 disks. In general, though, the organization of data on the disk 131, filed on Apr. 27, 2000, and Jul. 13, 2000, respectively, is similar. The disk surfaces are divided into multiple by Benedict Michael Rafanello, et al, are incorporated concentric rings, or tracks (31). Some disk drives, Such as herein by reference in their entireties, including drawings, hard disk drives, consist of multiple platters, in which case and hereby are made a part of this application. corresponding tracks on each platter are grouped into cyl inders. Each track is divided into multiple sectors (32) in BACKGROUND OF THE INVENTION which data can be Stored. 1. Field of the Invention Turning to FIG. 4, a computer disk drive (41) is repre Sented as an ordered collection of Sectors numbered 0 This invention relates to the arts of computer disk media, formatting of computer disks, organization of computer through “n”. The very first sector on the hard drive, sector readable media by operating Systems and device drivers, and 35 zero, contains the Master Boot Record (“MBR”). The MBR the management of logical Volumes of computer disks. In contains partition definitions for the rest of the disk. TABLE particular, this invention relates to improvements to the 1 shows a sample partial MBR. control of data and boot records Stored in logical Volumes TABLE 1. when the logical volumes comprise multiple layers of aggre 40 gation. Partition Table for 6 GB Drive 2. Description of the Related Art Start End Length Persistent and mass data Storage devices for computer Partition (cyl. side, sector) (cyl, side, sector) (sectors) Systems, especially those employed in personal computers, first 0, 1, 1 391, 254, 63 6297417 are well known within the art. Many are disk-based, Such as 45 floppy disks, removable hard disk drives (“HDD”), and second 392, 0, 1 783, 254, 63 629748O compact-disk read only memories (“CD-ROM"). FIG. 1 shows a typical personal computer System (1) architecture, For the disk partitioning shown in TABLE 1, the MBR is wherein a CPU (2) interfaces to a variety of I/O devices such located in the first sector on side 0 at cylinder 0 sector 1. The as a keyboard (3), monitor or display (5) and a mouse (4). 50 MBR requires only one sector, but the entire track of 63 The CPU (2) also may interface to a number of storage Sectors is “blocked' for the use of the MBR, 62 sectors of peripherals including CD-ROM drives (7), hard disk drives side 0 cylinder 0 are left unused. (6), and floppy drives (5). Typically, floppy disk drives The partition table has entries in it defining two types of interface to the CPU via Integrated Drive Electronics partitions: primary and extended. Conventional disk format (“IDE') (8), but this interface may alternately be one of 55 ting Schemes allow only one extended partition (411) to be Several other Standard interfaces or a proprietary interface. defined. P1 (43) and P2 (44) are primary partitions. The The hard disk drives (6) and CD-ROM drives (7) may order and locations of the primary and extended partitions interface to the CPU (2) via an IDE or Small Computer may vary, but invariably there are entries in the partition System Interface (“SCSI”), as shown (9). table of the MBR which defines them. FIG. 2 shows a generalization of the hardware, firmware 60 The extended partition (411) is defined in the partition and Software organization of a personal computer System table in the MBR as a Single partition using a single entry in (20). The hardware group (21) includes the persistent stor the MBR partition table. Basically, this entry in the MBR age devices discussed Supra, as well as other System hard just indicates to the computer operating System that inside of ware components Such as a real-time clock, keyboard this extended partition can be found other partitions and controller, display adapter, etc. A basic input/output System 65 partition definitions. The operating System typically assigns (“BIOS") (22) provides the direct firmware control of these logical drive letters and/or logical volumes to these System components typically. An operating System (24) Such partitions, or groups of partitions. US 6,711591 B1 3 4 In order to determine the Size and location of the partitions Volume form a Stack, and I/O requests are processed from within the extended partition, the operating System accesses the top most layer down the Stack to the bottom most layer.
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