Concatenated Metadevices - Lucent Technologies CentreVu Release 3 Version 8 Disk-Mirrored Systems User Manual

Introduction to Disk Mirroring
Disk mirroring defined
Concatenated
metadevices
CentreVu CMS Release 3 Version 8 Disk-Mirrored Systems
The illustration below shows a simple, two-slice metadevice.
Physical Disks A & B
c0t0d0s2
c1t0d0s2
A metadevice can be configured as any one of three basic types: striped,
concatenated, or concatenated stripes . The type used by CMS systems
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is the concatenated metadevice. In a concatenated metadevice, data
blocks, or chunks , are written sequentially across the slices, beginning
with the first disk.
Consider, for example, a concatenated metadevice with three slices (see
the illustration below.) In that scenario, disk A can be envisioned as
containing logical chunks 1 through 4, disk B as containing logical
chunks 5 through 8, and disk C as containing chunks 9 through 12.
Physical Disk A
Chunk 1
Chunk 2
Chunk 3
Chunk 4
Physical Disk B
Chunk 5
Chunk 6
Chunk 7
Chunk 8
Physical Disk C
Chunk 9
Chunk 10
Chunk 11
Chunk 12
Metadevice d0
c0t0d0s2
c1t0d0s2
Metadevice d1
Chunk 1
Chunk 2
. . .
Solstice DiskSuite
. . .
. . .
Chunk 12
2