title: resize2fs: Bad magic number in super-block while trying to open
body: <p>I am trying to resize a logical volume on CentOS7 but am running into the following error:</p>
  
  <pre><code>resize2fs 1.42.9 (28-Dec-2013)
  resize2fs: Bad magic number in super-block while trying to open /dev/mapper/centos-root
  Couldn't find valid filesystem superblock.
  </code></pre>
  
  <p>I have tried adding a new partition (using fdisk) and using vgextend to extend the volume group, then resizing.
  Resize worked fine for the logical volume using lvextend, but it failed at resize2fs.</p>
  
  <p>I have also tried deleting an existing partition (using fdisk) and recreating it with a larger end block, then resizing the physical volume using lvm pvresize, followed by a resize of the logical volume using lvm lvresize. Again everything worked fine up to this point.</p>
  
  <p>Once I tried to use resize2fs, using both methods as above, I received the exact same error.</p>
  
  <p>Hopefully some of the following will shed some light.</p>
  
  <p>fdisk -l</p>
  
  <pre><code>[root@server~]# fdisk -l
  
  Disk /dev/xvda: 32.2 GB, 32212254720 bytes, 62914560 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk label type: dos
  Disk identifier: 0x0009323a
  
  Device Boot      Start         End      Blocks   Id  System
  /dev/xvda1   *        2048     1026047      512000   83  Linux
  /dev/xvda2         1026048    41943039    20458496   8e  Linux LVM
  /dev/xvda3        41943040    62914559    10485760   8e  Linux LVM
  
  Disk /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  
  
  Disk /dev/mapper/centos-root: 29.5 GB, 29532094464 bytes, 57679872 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  </code></pre>
  
  <p>pvdisplay</p>
  
  <pre><code>[root@server ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/xvda2
  VG Name               centos
  PV Size               19.51 GiB / not usable 2.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              4994
  Free PE               0
  Allocated PE          4994
  PV UUID               7bJOPh-OUK0-dGAs-2yqL-CAsV-TZeL-HfYzCt
  
  --- Physical volume ---
  PV Name               /dev/xvda3
  VG Name               centos
  PV Size               10.00 GiB / not usable 4.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              2559
  Free PE               0
  Allocated PE          2559
  PV UUID               p0IClg-5mrh-5WlL-eJ1v-t6Tm-flVJ-gsJOK6
  </code></pre>
  
  <p>vgdisplay</p>
  
  <pre><code>[root@server ~]# vgdisplay
  --- Volume group ---
  VG Name               centos
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               29.50 GiB
  PE Size               4.00 MiB
  Total PE              7553
  Alloc PE / Size       7553 / 29.50 GiB
  Free  PE / Size       0 / 0
  VG UUID               FD7k1M-koJt-2veW-sizL-Srsq-Y6zt-GcCfz6
  </code></pre>
  
  <p>lvdisplay</p>
  
  <pre><code>[root@server ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/centos/swap
  LV Name                swap
  VG Name                centos
  LV UUID                KyokrR-NGsp-6jVA-P92S-QE3X-hvdp-WAeACd
  LV Write Access        read/write
  LV Creation host, time localhost, 2014-10-09 08:28:42 +0100
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0
  
  --- Logical volume ---
  LV Path                /dev/centos/root
  LV Name                root
  VG Name                centos
  LV UUID                ugCOcT-sTDK-M8EV-3InM-hjIg-2nwS-KeAOnq
  LV Write Access        read/write
  LV Creation host, time localhost, 2014-10-09 08:28:42 +0100
  LV Status              available
  # open                 1
  LV Size                27.50 GiB
  Current LE             7041
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1
  </code></pre>
  
  <p>I've probably done something stupid, so any help would be greatly appreciated!</p>