Unable to mount cinder volume of ceph back-end inside the instance

Issue

• mounting of cinder volume of ceph back-end inside the instance instance fails with I/O error :

[  164.966649] blk_update_request: I/O error, dev vdb, sector 0
[  164.967942] Buffer I/O error on dev vdb, logical block 0, lost async page write
[  164.968885] blk_update_request: I/O error, dev vdb, sector 16
[  164.969652] Buffer I/O error on dev vdb, logical block 2, lost async page write
[  164.970633] Buffer I/O error on dev vdb, logical block 3, lost async page write
[  164.971711] Buffer I/O error on dev vdb, logical block 4, lost async page write
[  164.972838] Buffer I/O error on dev vdb, logical block 5, lost async page write
[  164.974001] Buffer I/O error on dev vdb, logical block 6, lost async page write
[  164.975050] Buffer I/O error on dev vdb, logical block 7, lost async page write
[  164.976249] Buffer I/O error on dev vdb, logical block 8, lost async page write
[  164.977188] Buffer I/O error on dev vdb, logical block 9, lost async page write
[  164.978043] Buffer I/O error on dev vdb, logical block 10, lost async page write
[  164.978930] blk_update_request: I/O error, dev vdb, sector 29360128
[  164.983874] blk_update_request: I/O error, dev vdb, sector 29360208
[  164.992586] blk_update_request: I/O error, dev vdb, sector 29360264
[  165.000701] blk_update_request: I/O error, dev vdb, sector 29366384
[  165.010514] blk_update_request: I/O error, dev vdb, sector 29368784
[  165.018809] blk_update_request: I/O error, dev vdb, sector 29435544
[  165.026458] blk_update_request: I/O error, dev vdb, sector 29452288
[  165.034674] blk_update_request: I/O error, dev vdb, sector 33554432

• snapshot creation of cinder volume fails with below error in volume.log :

ReadOnlyImage: [errno 30] error creating snapshot when creating a snapshot from Cinder