Hi Everybody, I've recently come across some RAID-Recovery problem that were kind of not-so-easy-to-understand. I was trying to recover damaged RAID5s, where one disk died and another dropped out (most likely due to read error recovery timeout / not reporting back while error recovery was active) during resync with a spare/new disk. After taking double backups I tried to recreate the raid with the needed working disk images (to make the superblocks consistent). During that action mdadm told me that the last-dropped disk contained a valid ext3 filesystem and was obviously part of an md-array. This happened with NAS-Devices from 2 different Vendors (namely Thecus and Synology), which made me think it must be a md-raid thing. Does md-raid create a filesystem after a disk dropped out? Or may something in the system happen to cause this strange behaviour? All in all: after recreating the raids the filesystem contained on it was totally damaged (could not even be mounted). fsck ran multiple days with excessive data loss. P.S.: the mdadm-lines to recreate the RAIDs were derived from mdadm -E - outputs of the original partitions, so I believe that it should have worked (on other recoveries I did before it also worked well). Does anyone have an idea what is going on there? Or may it have happened - well, I don't want to say something that could get me sued. All the best, Stefan Hübner -- 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
