Increase size of a volume group

Question

I have a 16GB msata but my rootfs is only 4GB. I need to increase the size of a volume group /dev/mapper/vg-var/ for my embedded system to full capacity.

$ lsblk
NAME           MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda              8:0    0 14.9G  0 disk
|-sda1           8:1    0 39.2M  0 part
`-sda2           8:2    0  3.7G  0 part
  |-vg-system1 254:0    0  800M  0 lvm  /
  |-vg-system2 254:1    0  800M  0 lvm
  `-vg-var     254:2    0  2.1G  0 lvm  /var


$ df -Th
Filesystem           Type            Size      Used Available Use% Mounted on
tmpfs                tmpfs         890.7M    104.0K    890.6M   0% /tmp
tmpfs                tmpfs         890.7M    484.0K    890.2M   0% /run
devtmpfs             devtmpfs      888.1M         0    888.1M   0% /dev
/dev/mapper/vg-system1
                     ext3          771.4M    549.6M    181.8M  75% /
tmpfs                tmpfs         890.7M         0    890.7M   0% /dev/shm
/dev/mapper/vg-var   ext3            2.0G      3.5M      1.9G   0% /var


$ sudo vgs
  VG #PV #LV #SN Attr   VSize VFree
  vg   1   3   0 wz--n- 3.68g    0

How should i proceed ? Do i Need to extend /dev/sda2 first with fdisk ?

Answer 1

1. Resize the /dev/sda2 partition with fdisk or parted
2. Resize the PV format on /dev/sda2 with pvresize /dev/sda2
3. Resize the logical volumes you want to resize with lvresize -L+<size> --resizefs /dev/vg/var (to resize your /var) or lvresize --resizefs -L+<size> /dev/vg/system1 (to resize your /). <size> can be either 100%FREE to use all free space available or something 1G to add 1 GB. So to resize your / to use all available free space you'd use lvresize --resizefs -L+100%FREE /dev/vg/system1