Several issues while working with LVM volumes

[jbianquetti-nami]

Our setup includes a root device with LVM volume (Ubuntu 16.04 on AWS)

fdisk -l output:

Device     Boot   Start      End  Sectors  Size Id Type
/dev/xvda1 *       2048  3905535  3903488  1.9G 83 Linux
/dev/xvda2      3905536 41940991 38035456 18.1G 8e Linux LVM

pvs output:

  PV         VG           Fmt  Attr PSize  PFree
  /dev/xvda2 vg0          lvm2 a--  18.13g  3.82g

We wanted to increase the root partition:

./embiggen-disk /
panic: TODO: handle other device types; ask kernel

I tweaked https://github.com/google/embiggen-disk/blob/505618620d725a031538556a826c83b2e1f431d1/part.go#L50 to accept /dev/xvd devices too, but the command says:

./embiggen-disk /
error: unknown MBR partition type "8e" for /dev/xvda2

Type 8e is Linux LVM. The error comes from https://github.com/google/embiggen-disk/blob/505618620d725a031538556a826c83b2e1f431d1/part.go#L97

Is this tool intended to deal with LVM volumes on MBR disks?

[bradfitz]

I've been meaning to add support for virtio-block devices (the /dev/xvd*) but wanted to add integration tests first, which I'm almost done with.

Likewise, adding "8e" is fine. The tool was just over-paranoid by default until I'd tested all the configurations, but it'll be paranoid later if it finds something amiss.

I'll keep this open until I fix both of these.

Thanks!