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Browse Prior Art Database

Mirroring of Data on a Partition Basis

IP.com Disclosure Number: IPCOM000103135D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 43K

Publishing Venue

IBM

Related People

Auslander, M: AUTHOR [+6]

Abstract

Disclosed is a technique for mirroring data on a partition basis.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Mirroring of Data on a Partition Basis

      Disclosed is a technique for mirroring data on a partition
basis.

      Mirroring is used to support replication of data for recovery
from media failures. Normally users have specific files or
filesystems that are essential and the loss of which would be
disastrous. Supporting mirroring only on a complete disk basis can
waste a considerable amount of disk space and result in more overhead
than is needed.

      A partition is a fixed sized, physically contiguous collection
of bytes on a single disk. A logical volume is a dynamically
expandable logical disk made up of one or more logical partitions.
Each logical partition is backed up by one or more physical
partitions. It is backed up by one if the partition is not mirrored,
by two if the partition is singly mirrored, and by three if the
partition is doubly mirrored.

      Mirroring can be selected in the following ways for each
logical volume. None of the logical partitions in a logical volume
can be mirrored. All of the logical partitions in a logical volume
can be mirrored. Selected logical partitions in a logical volume can
be mirrored. When selected mirroring is chosen only the file system
data is automatically mirrored. This consists of the super block,
inodes, indirect blocks, and directories. Also the user can specify
if a file's data is to be mirrored when the file is created on a
logical volume that is selectively mirrored.

      This technique pr...