Hi Amit, { Note, convention on kernel.org is to trim & bottom post, or interleave replies with trimmed context. } On 07/19/2016 10:52 PM, Bhatia Amit wrote: > Hi Phil > > One more thing. When the enclosure became inaccesible in June 2016, > WDC gave me a new unit with drives. I dont remember for sure, but I > think I first replaced drive A from new enclosure with the Drive A > (currently in discussion) from old enclosure, hoping new unit would > reconfigure based on info from old drive. But I was not able to > access the unit. Then I put back the two new drives back in new > enclosure, configured new unit for RAID1 and then replaced the drive > A again with the drive A from old enclosure, but again no luck > accessing it (Error Message=Unable to mount). Since the default > configuration of a new configuration is Striping and not RAID1, > probably the first action (replacing drive A before configuring new > unit for RAID1), might have been the cause why this drive A shows as > RAID=linear, rather than RAID1. That could explain it, but I would have expected your mount of /dev/sdc4 to succeed. Your dmesg excerpt clearly shows a raid1 binding on partition 4, so the metadata on the drive you are examining must be wrong. The only way I know for that to happen is if there are multiple superblocks on the drive, and a plain examine is finding the v1.0 metadata first. I'm not sure if this is supported, by try specifying the version along with --examine for each of v0.90, v1.0, v1.1, and v1.2 to see if any difference shows. Paste the results from each. Phil -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html