公开(公告)号：JP2000353115A

公开(公告)日：2000-12-19

申请号：JP2000130681

申请日：2000-04-28

Applicant: EMC CORP

Inventor： CROW PRESTON F ,  MASON ROBERT S JR ,  STEPHEN T MCCLURE ,  SUSAN C NAGY ,  WHEELER RICHARD G

IPC: G06F12/00 ,  G06F17/30

Abstract: PROBLEM TO BE SOLVED: To obtain a more flexible method for extending an existent file by allowing each (i) nodes to have multiple lines and storing extent indicating data blocks in some of the lines. SOLUTION: A physical structure includes directories 61 and 62 and (i) nodes 63 and 64. The directory 61 converts abstract file names and directory names to the physical addresses of the (i) nodes 63 and 64 and directory 62. The (i) nodes 63 and 64 stores a list of extents 65 to 66 wherein successive file segments are mapped to strings of physical data blocks 80 to 82, 84 to 85, and 92 to 94. The physical directories 61 and 62 and (i) nodes 63 and 64 are stored in a global cache memory. Copies of relative physical directories 61 and 62 and/or (i) nodes 63 and 64 are also locally stored in volatile memories of a processor and a driver.

公开(公告)号：EP1018072A4

公开(公告)日：2003-01-02

申请号：EP98948407

申请日：1998-09-21

Applicant: EMC CORP

Inventor： MASON ROBERT S JR ,  OFEK YUVAL ,  VISHLITZKY NATAN ,  ARNON DAN ,  BACHMAT EITAN

IPC: G06F3/06 ,  G06F3/00 ,  G06F9/00 ,  G06F11/20 ,  G06F12/00 ,  G06F13/00

CPC classification number: G06F11/2066 ,  G06F3/0601 ,  G06F11/2069 ,  G06F2003/0697

Abstract: The invention relates generally to mass storage systems, and in particular to mass storage systems in which stored logical volumes are duplicated in mirrored form. The system includes a method for dynamically adjusting the mirror service policy for a disk drive system by periodically collecting statistics (101) describing the reading and writing of data to mirrored logical volumes of the system in successive time periods and determining, from time to time, from the collected statistics, whether the mirror service policy should continue or should change (104). In particular, the system takes into account activity levels at the physical devices and results in more efficient accessing of logical volume pairs as well as a better balance of loading and accessing the logical volumes.