Hi all, We are working on jewel branch on a test cluster to validate some of the fixes. But landed up in the following error when mapping an image using krbd on Ubuntu 14.04.2 with 3.16.0-55 kernel version. $ sudo rbd map -p pool1 rbd1 rbd: sysfs write failed rbd: map failed: (5) Input/output error $ uname -a Linux 3.16.0-55-generic #74~14.04.1-Ubuntu SMP Tue Nov 17 10:15:59 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux $dmesg .... [11082.199006] libceph: read_partial_message bad hdr crc 2112154322 != expected 0 [11082.209414] libceph: mon0 x.x.x.x:6789 socket error on read [11092.238317] libceph: read_partial_message bad hdr crc 2112154322 != expected 0 [11092.248982] libceph: mon0 x.x.x.x:6789 socket error on read ..... When I looked at the ceph_msg_header on 3.16 kernel (http://lxr.free-electrons.com/source/include/linux/ceph/msgr.h?v=3.16) There is one field change from jewel branch 145 struct ceph_msg_header { ....... 159 160 /* oldest code we think can decode this. unknown if zero. */ 161 __le16 compat_version; <<< New one, which is present from 3.19 onwards 162 __le16 reserved; 163 __le32 crc; /* header crc32c */ 164 } __attribute__ ((packed)); How can map the image in 3.16 kernel apart from upgrading the kernel? Do we have any branch where I can build the modules with latest changes? Regards, Varada -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html