“resize2fs: Permission denied to resize filesystem”

The Problem

On CentOS/RHEL 6, an LVM volume group size has been extended and an attempt to do online resize of ext4 filesystem on LVM volume group failed with following error.

resize2fs /dev/mapper/P05TRF1vg-vol_controlm
resize2fs 1.43-WIP (20-Jun-2013)
Filesystem at /dev/mapper/P05TRF1vg-vol_controlm is mounted on /controlM; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 1
resize2fs: Permission denied to resize filesystem

The Solution

A file system inconsistency blocked the online resize of the disk, which can be observed in the messages as logged below:

--message--
kernel: EXT4-fs warning (device dm-1): ext4_resize_begin:32: There are errors in the filesystem, so online resizing is not allowed

--dmesg--
EXT4-fs (dm-4): warning: mounting fs with errors, running e2fsck is recommended

Since the file system is in an inconsistent state, a file system check is required for this affected file system, so online resizing is not possible and the file system has to be unmounted.

1. Umount the file system.

# umount /controlM

2. Perform a file system check.

# e2fsck -y /dev/mapper/P05TRF1vg-vol_controlm

3. Resize the file system.

# resize2fs /dev/mapper/P05TRF1vg-vol_controlm

4. Remount the file system:

# mount /dev/mapper/P05TRF1vg-vol_controlm /controlM

5. Check if the file system has been resized.

# df -h

Note: You can refer “man e2fsck” if you want to know more about this command.

# man e2fsck