Nested LVM

[root@xen-home srv]# vgs
  VG       #PV #LV #SN Attr   VSize  VFree
  VolGroup   1   2   0 wz--n- 17.51g    0
  vg00       2  10   0 wz--n-  1.82t 1.71t

[root@xen-home srv]# lvs
  LV      VG       Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  lv_root VolGroup -wi------- 16.51g
  lv_swap VolGroup -wi-------  1.00g
  lv01    vg00     -wi-a-----  5.00g
  lv02    vg00     -wi-a-----  5.00g
  lv03    vg00     -wi-a-----  5.00g
  lv04    vg00     -wi-a-----  5.00g
  lv05    vg00     -wi-a-----  5.00g
  lv06    vg00     -wi-ao---- 20.00g
  lv_root vg00     rwi-aor---  5.00g                                    100.00
  lv_srv  vg00     -wi-ao---- 30.00g
  lv_swap vg00     rwi-aor---  8.00g                                    100.00
  lv_var  vg00     rwi-aor---  5.00g                                    100.00

[root@xen-home srv]# lvdisplay VolGroup/lv_root
  --- Logical volume ---
  LV Path                /dev/VolGroup/lv_root
  LV Name                lv_root
  VG Name                VolGroup
  LV UUID                DA53Rd-dRa3-CNRP-Jmb8-S7vl-1uAC-Anlxg0
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2013-03-08 23:56:11 -0800
  LV Status              NOT available
  LV Size                16.51 GiB
  Current LE             4226
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto

[root@xen-home srv]# ll /dev/VolGroup/lv_root
ls: cannot access /dev/VolGroup/lv_root: No such file or directory

[root@xen-home srv]# lvchange -a y VolGroup/lv_root

[root@xen-home srv]# lvdisplay VolGroup/lv_root
  --- Logical volume ---
  LV Path                /dev/VolGroup/lv_root
  LV Name                lv_root
  VG Name                VolGroup
  LV UUID                DA53Rd-dRa3-CNRP-Jmb8-S7vl-1uAC-Anlxg0
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2013-03-08 23:56:11 -0800
  LV Status              available
  # open                 0
  LV Size                16.51 GiB
  Current LE             4226
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:24

[root@xen-home srv]# ll /dev/VolGroup/lv_root
lrwxrwxrwx 1 root root 8 Sep  8 11:04 /dev/VolGroup/lv_root -> ../dm-24