Hi, On our Ceph cluster from time to time we have some inconsistent PGs (after deep-scrub). We have some issues with disk/sata cables/lsi controller causing IO errors from time to time (but that's not the point in this case). When IO error occurs on OSD journal partition everything works as is should -> OSD is crashed and that's ok - Ceph will handle that. But when IO error occurs on OSD data partition during journal flush OSD continue to work. After calling *writev* (in buffer::list::write_fd) OSD does check return code from this call but does NOT verify if write has been successful to disk (data are still only in memory and there is no fsync). That way OSD thinks that data has been stored on disk but it might be discarded (during sync dirty page will be reclaimed and you'll see "lost page write due to I/O error" in dmesg). Since there is no checksumming of data I just wanted to make sure that this is by design. Maybe there is a way to tell OSD to call fsync after write and have data consistent? -- Cheers, PS -- 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
