HP-UX HB v13.00 Ch-13 - LVM

HP-UX Handbook – Rev 13.00 Page 19 (of 110)
Chapter 13 LVM
October 29, 2013
Calculating an optimal extent size for a version 2.x volume
group.
Like Version 1.0 Volume Groups, there is a relationship between extent size and
maximum volume group size. There is also a limitation on the number of extents an
individual volume group can contain. To determine the proper size, the vgcreate
command has a new –E option. This option displays the maximum volume group size
based on the given physical extent size or minimum physical extent size based on the
maximum volume group size.
Example
After you know the VG size you want to provision for, use vgcreate with the –E option to
determine the minimum extent size required to achieve it.
What is the minimum extent size to provision a 2.0 VG for 1 PB?
# vgcreate -V 2.0 -E -S 1p
Max_VG_size=1p:extent_size=32m
What is the maximum 2.0 volume group size with an extent size of 16MB?
#vgcreate -V 2.0 -E -s 16
Max_VG_size=512t:extent_size=16m
Supported file and file system sizes
It may be possible to create files or file systems larger than these documented limits,
such files and file systems are not supported and the results of using them may be
unpredictable.
The OnlineJFS and HFS supported size could be found in the JFS/OnlieJFS chapter.