Thin-Provisioned Volumes - IBM Storwize V5010 Manual

Table 6-1 shows you the bitmap space default configuration.
Table 6-1 Bitmap space default configuration
Copy service
Remote copy
FlashCopy
Volume
mirroring
RAID
a. The actual amount of functionality might increase based on settings such as grain size and strip
size. RAID is subject to a 15% margin or error.
b. Remote copy includes Metro Mirror, Global Mirror, and active-active relationships.
c. FlashCopy includes the FlashCopy function, Global Mirror with change volumes, and
active-active relationships.
The sum of all bitmap memory allocation for all functions except FlashCopy must not exceed
552 MiB.

6.1.5 Thin-provisioned volumes

Volumes can be configured to be thin-provisioned or fully allocated. A
volume behaves as though application reads and writes were fully allocated. When a
thin-provisioned volume is created, the user specifies two capacities:
The real physical capacity that is allocated to the volume from the storage pool
Its virtual capacity that is available to the host
fully allocated
In a
Therefore, the real capacity determines the quantity of MDisk extents that is initially allocated
to the volume. The
IBM Spectrum Virtualize components (for example, FlashCopy, cache, and remote copy), and
to the host servers.
real capacity
The
volume. The real capacity can be specified as an absolute value, or as a percentage of the
virtual capacity.
Minimum Default
allocated allocated
bitmap bitmap
space space
b
0
c
0
0
0
volume, these two values are the same.
virtual capacity
is used to store the user data and the metadata for the thin-provisioned
Maximum
allocated
bitmap
space
20 MiB 512 MiB
20 MiB 2 GiB
20 MiB 512 MiB
40 MiB 512 MiB
is the capacity of the volume that is reported to all other
Chapter 6. Volume configuration
a
Minimum functionality
when using the default
values
40 TiB of remote mirroring
volume capacity
10 TiB of FlashCopy
source volume capacity
5 TiB of incremental
FlashCopy source volume
capacity
40 TiB of mirrored volumes
80 TiB array capacity
using RAID 0, 1, or 10
80 TiB array capacity in
three-disk RAID 5 array
Slightly less than 120 TiB
array capacity in five-disk
RAID 6 array
thin-provisioned
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