How to mount HDD extracted from singledrive ZyXEL NAS?

Question

Gparted Information and Warning:

<i>Filesystem volume name:   <none>
Last mounted on:          /i-data/f128dac5
Filesystem UUID:          c2f55399-a8ab-400b-a144-d605ceb58c9d
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         unsigned_directory_hash 
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              122068992
Block count:              488249472
Reserved block count:     0
Free blocks:              480389347
Free inodes:              122066932
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      907
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Flex block group size:    16
Filesystem created:       Fri May 25 16:45:58 2012
Last mount time:          Wed Dec 31 17:14:27 2014
Last write time:          Wed Dec 31 17:29:55 2014
Mount count:              369
Maximum mount count:      21
Last checked:             Fri May 25 16:58:00 2012
Check interval:           15552000 (6 months)
Next check after:         Wed Nov 21 15:58:00 2012
Lifetime writes:          2351 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:           256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      bc641083-df73-4c0a-8560-ac502897cba0
Journal backup:           inode blocks</i>

<i>dumpe2fs 1.42.12 (29-Aug-2014)
dumpe2fs: A block group is missing an inode table while reading journal inode</i>

<i>Unable to read the contents of this file system!
Because of this some operations may be unavailable.
The cause might be a missing software package.
The following list of software packages is required for ext4 file system support:  e2fsprogs v1.41+.</i>

e2fsprogs is installed and its version is 1.42. It's on Debian 8.3.

Answer 1

First, if you do not have mdadm (man page) installed, you need to install it now:

sudo apt-get install mdadm

Supposing the drive's name is /dev/sdx, and we are interested in second partition, and supposing we already have some array on the system, so we name it for instance /dev/md9, we assemble the one-drive array as follows:

sudo mdadm --assemble --force /dev/md9 /dev/sdx2

If that went well, create some directory for the mount point, e.g:

sudo mkdir --mode=755 /mnt/zyxelnas

Finally, mount it as follows:

sudo mount /dev/md9 /mnt/zyxelnas