Following derobert's trick to resize the underlying filesystem when resizing a LVM volume:
lvm> lvextend -r -l +100%FREE /dev/VolGroup00/lvolhome fsck from util-linux 2.25.2 /sbin/fsck.btrfs: BTRFS file system. Size of logical volume VolGroup00/lvolhome changed from 3.04 GiB (777 extents) to 14.94 GiB (3824 extents). Logical volume lvolhome successfully resized fsadm: Filesystem "btrfs" on device "/dev/mapper/VolGroup00-lvolhome" is not supported by this tool fsadm failed: 1
The "problem" is that fsadm tool doesn't support btrfs resizing. Dispirited, I decided to do it the hard way (aka manually):
sudo btrfs filesystem resize max /dev/mapper/VolGroup00-lvolhome ERROR: can't access '/dev/mapper/VolGroup00-lvolhome'
Well, btrfs can't "access" the device, but it can detect it:
> sudo btrfs filesystem show Label: none uuid: 53330630-9670-4110-8f04-5a39bfa86478 Total devices 1 FS bytes used 2.75GiB devid 1 size 3.04GiB used 3.03GiB path /dev/mapper/VolGroup00-lvolhome
So, what gives? How to resize my btrfs partition inside the logical volume?