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Browse Prior Art Database

DASD Array Recovery Mechanism

IP.com Disclosure Number: IPCOM000115609D
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Ouchi, NK: AUTHOR

Abstract

Data from a failed domain are recovered to a spare domain. The functioning units in failed domains are recovered by reconstruction into a new domain where one or more other devices may be exchanged to create a new spare domain. 1. A method for managing access to a plurality of DASDs forming a storage subsystem, comprising the steps of: 2. statically configuring subsets of N DASDs into at least two multiple failure independent parity domains and reserving at least one of the domains as a spare, each domain including at lease a pair of DASDs; 3. responsive to a data string applied to the storage subsystem, segmenting said string, deriving parity thereover, and writing the segments and parity to counterpart DASDs in a selected one of the parity domains; 4.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

DASD Array Recovery Mechanism

      Data from a failed domain are recovered to a spare domain.  The
functioning units in failed domains are recovered by reconstruction
into a new domain where one or more other devices may be exchanged to
create a new spare domain.
  1.  A method for managing access to a plurality of DASDs forming a
       storage subsystem, comprising the steps of:
  2.  statically configuring subsets of N DASDs into at least two
       multiple failure independent parity domains and reserving at
       least one of the domains as a spare, each domain including at
       lease a pair of DASDs;
  3.  responsive to a data string applied to the storage subsystem,
       segmenting said string, deriving parity thereover, and writing
       the segments and parity to counterpart DASDs in a selected one
of
       the parity domains;
  4.  detecting a failed DASD on any one of the parity domains;
  5.  responsive to the detection, rebuilding and rewriting the
       contents stored on the parity domain containing the failed
DASD
       onto the spare domain.
  6.  The method according to claim 1, wherein said reconfiguration
       includes statically forming a new domain from the available
DASDs
       of two or more failed parity domains resulting in at least one
       parity domain with no failed DASDs.