The pvdisplay
command has a -m
option to show the mapping of physical extents to logical volumes and logical extents.
I have set up the following situation on a test machine:
- 3 disks of 1GB each added to the system and used as physical volumes for vg_test
- 6 logical volumes made with various sizes (ranging from 300M to 1.1G) so that they are spread over the physical volumes
Running pvdisplay -m
on this machine results in the following output:
[root@centos6 ~]# pvdisplay -m
--- Physical volume ---
PV Name /dev/sdb
VG Name vg_test
PV Size 1.00 GiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 255
Free PE 5
Allocated PE 250
PV UUID eR2ko2-aKRf-uCfq-O2L0-z6em-ZYT5-23YhKb
--- Physical Segments ---
Physical extent 0 to 74:
Logical volume /dev/vg_test/one
Logical extents 0 to 74
Physical extent 75 to 149:
Logical volume /dev/vg_test/two
Logical extents 0 to 74
Physical extent 150 to 249:
Logical volume /dev/vg_test/four
Logical extents 0 to 99
Physical extent 250 to 254:
FREE
--- Physical volume ---
PV Name /dev/sdc
VG Name vg_test
PV Size 1.00 GiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 255
Free PE 10
Allocated PE 245
PV UUID rByjXK-NA6D-ifnY-lKdF-eFWg-Ndou-psGJUq
--- Physical Segments ---
Physical extent 0 to 124:
Logical volume /dev/vg_test/three
Logical extents 0 to 124
Physical extent 125 to 224:
Logical volume /dev/vg_test/five
Logical extents 0 to 99
Physical extent 225 to 244:
Logical volume /dev/vg_test/six
Logical extents 255 to 274
Physical extent 245 to 254:
FREE
--- Physical volume ---
PV Name /dev/sdd
VG Name vg_test
PV Size 1.00 GiB / not usable 4.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 255
Free PE 0
Allocated PE 255
PV UUID TCJnZM-0ss9-o5gY-lgD3-7Kq6-18IH-sN04To
--- Physical Segments ---
Physical extent 0 to 254:
Logical volume /dev/vg_test/six
Logical extents 0 to 254
As you can see, You get a nice overview of where the extents for each of the 6 logical volumes are.