LinuxQuestions.org - "Device is busy" message when trying to resize filesystem on encrypted LVM

Hi there,

I tried to extend my /home-partition on my CentOS 7.0.1406 installation today, following this guide: http://www.thomas-krenn.com/de/wiki/...C3%B6%C3%9Fern (which is in German)

Everything went perfectly until the step where I resize the underlying filesystem (which is ext4) with the command:

Code:

resize2fs -p /dev/dm-1

(which is what "df -h" showed me as the mount point for my /home-partition).

The error I get is:

Code:

"Invalid magic number in the superblock when trying to open /dev/dm-1. Cannot find a valid filesystem superblock."

(the message is in German, but this is what it translates to...)

When I check my logical volumes with "lvdisplay", it displays:

Code:

lvdisplay

  --- Logical volume ---

  LV Path                /dev/cl/00

  LV Name                00

  VG Name                cl

  LV UUID                pTp5dI-u3LX-wxdF-CUIl-rAsO-m18u-LHuLva

  LV Write Access        read/write

  LV Creation host, time localhost, 2014-07-09 18:14:35 +0200

  LV Status              available

  # open                1

  LV Size                200,00 GiB

  Current LE            51200

  Segments              3

  Allocation            inherit

  Read ahead sectors    auto

  - currently set to    8192

  Block device          253:0

so, I tried:

Code:

resize2fs -p /dev/cl/00

also, which produced a slightly different error:

Code:

"Device or resource is busy when trying to open /dev/cl/00. Cannot find a valid filesystem superblock."

The system is CentOS 7.0.1406, freshly installed, with the following partition layout (two HDDs -> 500GB on /dev/sda and 20GB SSD on /dev/sdb):

/dev/sda1 -> Windows boot partition
/dev/sda2 -> Windows partition
/dev/sda3 -> Linux SWAP partition
/dev/sda4 -> extended partition containing:
/dev/sda5 -> ext4 partition for CentOS 6.5 (my old system, still running in triple boot here)
/dev/sda6 -> the first partition I added to the LVM
/dev/sda7 -> the second partition I added to the LVM
/dev/sda8 -> ext4 encrypted LVM volume containing the /home-partition of CentOS 7

/dev/sdb1 -> CentOS 7's root-partition (not part of the LVM, not encrypted)

Why do I get the errors? Because my /home is mounted when I try resizing? But I thought ext4 can do online resize? Or is it because it's encrypted?

Thanks in advance! ;)

rokyo