On Sun, Mar 11, 2018 at 11:28:08PM +0700, Andreas Hild wrote: > Following a physical disk failure of a RAID1 array, I tried to mount > the remaining volume of a root partition with "-o degraded". For some > reason it ended up as read-only as described here: > https://btrfs.wiki.kernel.org/index.php/Gotchas#raid1_volumes_only_mountable_once_RW_if_degraded > > > How to precisely do this: dump, recreate and restore its contents? > Could someone please provided more details how to recover this volume > safely?
> Linux debian 4.9.0-4-amd64 #1 SMP Debian 4.9.65-3 (2017-12-03) x86_64 > GNU/Linux > [ 1313.279140] BTRFS warning (device sdb2): missing devices (1) > exceeds the limit (0), writeable mount is not allowed I'd recommend instead going with kernel 4.14 or newer (available in stretch-backports), which handles this case well without the need to restore. If there's no actual data loss (there shouldn't be, it's RAID1 with only a single device missing), you can mount degraded normally, then balance the data onto the new disk. Recovery with 4.9 is unpleasant. Meow! -- ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢠⠒⠀⣿⡁ A dumb species has no way to open a tuna can. ⢿⡄⠘⠷⠚⠋⠀ A smart species invents a can opener. ⠈⠳⣄⠀⠀⠀⠀ A master species delegates. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html