---- On Wed, 17 Oct 2018 17:57:25 -0700 Qu Wenruo <quwenruo.bt...@gmx.com> wrote ---- ... > > But after chrooting to update-initramfs and cataloging resulting image > > content, usb_storage and uas were present under /lib/modules/xxx already, > > and failing systems still just busybox without a real rootfs rather than > > launch systemd; even tried kernel option "rootwait" which had no effect on > > access to ext storage; udev still seems not to have noticed the ext drives > > once busybox had control. > > Still looks like a initramfs problem other than btrfs problem. > > In the busybox environment, have you tried listing /dev to see if that > external device is found?
agreed that initramfs smells bad, but it hadn't been a problem until btrfs mounts (external-raid) had to rely on the usb channel; in busybox, ext drives/partitions are all missing from /dev; can't tell why so, ahci and usb modules are loaded afaict > Since you have a busybox environment, have you checked if "btrfs" command > lives in the initramfs? yes btrfs command works from busybox > IIRC at least you need the following things/abilities to boot: > > 1) usb and sata drivers > Means you could see both devices in the busybox environment under /dev > > 2) "Btrfs" command > Mostly for scan > Then you could try the following commands under busybox environment: > # btrfs device scan > # mount <device> <some temporary mount point> "btrfs dev scan" runs but doesn't indicate recognizing any; since raid1 conversion, ext drives are required for any btrfs mounts to be seen whole. When manually trying to mount in busybox, it gives a similar error about missing external device by UUID_SUB > If it works, it may mean you're missing "btrfs device scan" during boot > so kernel can't see all RAID1 disks for btrfs and failed to boot. > > Please refer to your distribution initramfs creation tool to see how to > add that scan. (Some distro has special hook for btrfs to handle such case). may have to tweak the /etc/initramfs-tools/initramfs.conf or modules list; MODULES=dep setting might act better than MODULES=most will look into this further to see about contrasting block device modules between cindy and the others appreciate the timely response- TP
