Debian's default installer (1) can not create a BTRFS raid array during installation, and (2) installs to the default subvol of the BTRFS target. The default subvol is 5 (BTRFS root) unless (i) prior to installation a BTRFS file-system was created, (ii) the default subvol is set to something other than 5, and (iii) you do not format the installation target during install. This perspective benefits from https://aykevl.nl/2015/11/debian-btrfs-subvolume.
Can Debian install BTRFS to a pre-existing BTRFS RAID 6 array? If the array's default is set to ,say subvolid 257, can I install to array subvolume 257? The goal is to install to a subvolume on the array without disturbing date on other array subvolumes. I erred and shutdown my NAS during a balance. Grub lost track of my root. Root was on RAID 6 array subvolid 257. I can boot a different root from a USB flash drive but neither update-grub not install-grub sees my old root on array subvolid 257. I am happy to either recover or lose array subvolid 257 but do not want to lose data on other array subvol's. I prefer to have my root on the array rather than a flash drive. The balance completed successfully after I booted from the flash drive. I am running a debian back-ported 4.4.0 kernel with btrfs-progs v4.4 on both my flash drive and array subvolid 257. Both installs are UEFI. df -h reports: Filesystem Size Used Avail Use% Mounted on udev 10M 0 10M 0% /dev tmpfs 790M 8.6M 781M 2% /run /dev/sdb3 3.8G 1.1G 2.4G 31% / tmpfs 2.0G 0 2.0G 0% /dev/shm tmpfs 5.0M 0 5.0M 0% /run/lock tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup /dev/sdb1 93M 311K 93M 1% /boot/efi /dev/sde 22T 4.9T 13T 29% /lit -- 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
