resize2fs: Permission denied to resize filesystem

1. Umount the file system.

# umount /data
如无法卸载，需要查出有哪些进程占用lsof /data

2. Perform a file system check.

# e2fsck -y /dev/mapper/datalv

3. Resize the file system.

# resize2fs /dev/mapper/datalv

4. Remount the file system:

# mount /dev/mapper/data /data

5. Check if the file system has been resized.

# df -h

原文：https://www.cnblogs.com/yudai/p/13097489.html