I seem unable to convert an existing btrfs device array to RAID 10.
Since it's pretty much RAID 0 and 1 combined, and 5 and 6 are
unstable, it's what I would like to use.
After I did tried this with 4.19.2-arch1-1-ARCH and btrfs-progs v4.19,
I updated my system and tried btrfs balance again with this system
information:
[mikko@localhost lvdata]$ uname -a
Linux localhost 4.19.4-arch1-1-ARCH #1 SMP PREEMPT Fri Nov 23 09:06:58
UTC 2018 x86_64 GNU/Linux
[mikko@localhost lvdata]$ btrfs --version
btrfs-progs v4.19
[mikko@localhost lvdata]$ sudo btrfs fi show
Label: 'main1' uuid: c7cbb9c3-8c55-45f1-b03c-48992efe2f11
Total devices 1 FS bytes used 2.90TiB
devid 1 size 3.64TiB used 2.91TiB path /dev/mapper/main
Label: 'red' uuid: f3c781a8-0f3e-4019-acbf-0b783cf566d0
Total devices 2 FS bytes used 640.00KiB
devid 1 size 931.51GiB used 2.03GiB path /dev/mapper/red1
devid 2 size 931.51GiB used 2.03GiB path /dev/mapper/red2
[mikko@localhost lvdata]$ btrfs fi df /mnt/red/
Data, RAID1: total=1.00GiB, used=512.00KiB
System, RAID1: total=32.00MiB, used=16.00KiB
Metadata, RAID1: total=1.00GiB, used=112.00KiB
GlobalReserve, single: total=16.00MiB, used=0.00B
---
Here are the steps I originally used:
[mikko@localhost lvdata]$ sudo cryptsetup luksFormat -s 512
--use-random /dev/sdc
[mikko@localhost lvdata]$ sudo cryptsetup luksFormat -s 512
--use-random /dev/sdd
[mikko@localhost lvdata]$ sudo cryptsetup luksOpen /dev/sdc red1
[mikko@localhost lvdata]$ sudo cryptsetup luksOpen /dev/sdd red2
[mikko@localhost lvdata]$ sudo mkfs.btrfs -L red /dev/mapper/red1
btrfs-progs v4.19
See http://btrfs.wiki.kernel.org for more information.
Label: red
UUID: f3c781a8-0f3e-4019-acbf-0b783cf566d0
Node size: 16384
Sector size: 4096
Filesystem size: 931.51GiB
Block group profiles:
Data: single 8.00MiB
Metadata: DUP 1.00GiB
System: DUP 8.00MiB
SSD detected: no
Incompat features: extref, skinny-metadata
Number of devices: 1
Devices:
ID SIZE PATH
1 931.51GiB /dev/mapper/red1
[mikko@localhost lvdata]$ sudo mount -t btrfs -o
defaults,noatime,nodiratime,autodefrag,compress=lzo /dev/mapper/red1
/mnt/red
[mikko@localhost lvdata]$ sudo btrfs device add /dev/mapper/red2 /mnt/red
[mikko@localhost lvdata]$ sudo btrfs balance start -dconvert=raid10
-mconvert=raid10 /mnt/red
ERROR: error during balancing '/mnt/red': Invalid argument
There may be more info in syslog - try dmesg | tail
code 1
[mikko@localhost lvdata]$ dmesg | tail
[12026.263243] BTRFS info (device dm-1): disk space caching is enabled
[12026.263244] BTRFS info (device dm-1): has skinny extents
[12026.263245] BTRFS info (device dm-1): flagging fs with big metadata feature
[12026.275153] BTRFS info (device dm-1): checking UUID tree
[12195.431766] BTRFS info (device dm-1): enabling auto defrag
[12195.431769] BTRFS info (device dm-1): use lzo compression, level 0
[12195.431770] BTRFS info (device dm-1): disk space caching is enabled
[12195.431771] BTRFS info (device dm-1): has skinny extents
[12205.815941] BTRFS info (device dm-1): disk added /dev/mapper/red2
[12744.788747] BTRFS error (device dm-1): balance: invalid convert
data profile raid10
Converting to RAID 1 did work but what can I do to make it RAID 10?
With the up-to-date system it still says "invalid convert data profile
raid10".
