I/O errors during bootup after root snapshot merge in RHEL 6

Issue

After merging a snapshot of the root device, upon boot there were some errors:

dracut: Scanning devices sda2 sdb1  for LVM logical volumes vg_myhost/lv_root vg_myhost/lv_swap
dracut: inactive Original '/dev/vg_myhost/lv_root' [1.18 GiB] inherit
dracut: inactive '/dev/vg_myhost/lv_swap' [2.33 GiB] inherit
Buffer I/O error on device dm-3, logical block 309232
Buffer I/O error on device dm-3, logical block 309232
Buffer I/O error on device dm-3, logical block 309246
Buffer I/O error on device dm-3, logical block 309246
Buffer I/O error on device dm-3, logical block 0
Buffer I/O error on device dm-3, logical block 0
Buffer I/O error on device dm-3, logical block 1
Buffer I/O error on device dm-3, logical block 309247
Buffer I/O error on device dm-3, logical block 309247
EXT4-fs (dm-2): mounted filesystem with ordered data mode
dracut: Mounted root filesystem /dev/mapper/vg_myhost-lv_root
dracut: Loading SELinux policy
SELinux:  Disabled at runtime.
dracut: /sbin/load_policy: Can't load policy: No such file or directory
dracut: Switching root
        Welcome to Red Hat Enterprise Linux Server
        Press 'I' to enter interactive startup.
Starting udev: [  OK  ]
Setting hostname kvm-guest02:  [  OK  ]
ERROR: asr: reading /dev/dm-3[Input/output error]
ERROR: ddf1: reading /dev/dm-3[Input/output error]
ERROR: ddf1: reading /dev/dm-3[Input/output error]
ERROR: hpt37x: reading /dev/dm-3[Input/output error]
ERROR: hpt45x: reading /dev/dm-3[Input/output error]
ERROR: isw: reading /dev/dm-3[Input/output error]
ERROR: jmicron: reading /dev/dm-3[Input/output error]
ERROR: lsi: reading /dev/dm-3[Input/output error]
ERROR: nvidia: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: pdc: reading /dev/dm-3[Input/output error]
ERROR: sil: reading /dev/dm-3[Input/output error]
ERROR: via: reading /dev/dm-3[Input/output error]
Setting up Logical Volume Management:   2 logical volume(s) in volume group "vg_myhost" now active
[  OK  ]