Scan LVM partition

If your OS partition die, but data in other disks run LVM, you can reinstall OS and mount logical volume to use.

Example
# pvscan
  PV /dev/vdb   VG vgdata   lvm2 [20,00 GiB / 5,00 GiB free]
  Total: 1 [20,00 GiB] / in use: 1 [20,00 GiB] / in no VG: 0 [0   ]

# vgscan 

  Reading all physical volumes.  This may take a while...

  Found volume group "vgdata" using metadata type lvm2

# vgchange -a y

  1 logical volume(s) in volume group "vgdata" now active

# lvscan 

  ACTIVE            '/dev/vgdata/lvdata' [15,00 GiB] inherit

# mount /dev/vgdata/lvdata /mnt

DONE

Disable IPv6 when using apt-get

Sometimes when run command apt-get update, it connected to some repo using IPv6 address. But it made long delay because ISP's network was not ready for IPv6.
Config make use IPv4
- Add -o Acquire::ForceIPv4=true when run apt-get
- Make config persistent:

# echo 'Acquire::ForceIPv4 "true";' | tee /etc/apt/apt.conf.d/99force-ipv4