LVM Version 2.0 Volume Groups in HP-UX 11i v3 (September 2008)

Maximal memory footprint, all extents allocated, max number of LVs and
PVs (2.0 solid lines, 1.0 dotted lines)
1
10
100
1000
1/
1
6
1/
8
1/
4
1/
2
1
2
4
8
16
32
6
4
128
2
56
512
102
4
2
0
4
8
Volume group size (tb) (all extents are allocated)
Memory footprint (mb)
1 mb extent 1.0
1 mb extent 2.0
2 mb extent 1.0
2 mb extent 2.0
4 mb extent 1.0
4 mb extent 2.0
8 mb extent 1.0
8 mb extent 2.0
16 mb extent 1.0
16 mb extent 2.0
32 mb extent 1.0
32 mb extent 2.0
64 mb extent 1.0
64 mb extent 2.0
128 mb extent 1.0
128 mb extent 2.0
256 mb extent 1.0
256 mb extent 2.0
Figure 4
Notes:
• For a given extent size, the 2.0 line goes further right compared to the 1.0 line because a 2.0 volume
group can be bigger.
• The 2.0 lines do not go farther up and right because of the limit of 32 million extents per volume group.
For the same volume group size and same extent size, a 2.0 volume group uses about 10 MB more than 1.0
because of the following reasons:
• A 2.0 volume group at the maximum contains 511 logical volumes and 511 physical volumes
while a 1.0 volume group is limited to only 255 logical volumes and 255 physical volumes
• The10 MB increase enables the removal of the 1.0 limitations (for example, logical volume size
and number of extents per physical volume or logical volumes) and enables new features such as
storing the logical volume name in the metadata.
Comparison of Volume Group Memory Footprints for the Same Number of
Logical and Physical Volumes
This comparison uses 255 logical volumes and 10 or 100 physical volumes per volume group. Figure 5 uses an
extent size of 8 MB while Figure 6 uses 64 MB.
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