On Tue, Mar 26, 2019 at 8:19 AM Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote: > > > > Kernel 4.20.17 > > btrfs-progs 4.20.2 > > > > The filesystem consists of 4 (HW raid6) devices, each of them shows different superblock backups but my hope is that backup 2 is "consistent" across all of them. > > > > Is there any way to restore a specific superblock backup and attempt to mount the filesystem? Running "btrfs restore" did partially recover the data, but the most important bit is still missing. > > You sda and sdb are at gen 60233 while sdd and sde are at gen 60234. > > It's possible to allow kernel to manually assemble its device list using > "device=" mount option. > > Since you're using RAID6, it's possible to recover using 2 devices only, > but in that case you need "degraded" mount option. He has btrfs raid0 profile on top of hardware RAID6 devices.
