I'm attempting to create an LVM volume on a bcache device, but getting "device not found or recognized", despite lsblk clearly showing the device, and bcache state showing "clean".
OS is Ubuntu 13.10 using a default kernel and bcache-tools come from https://launchpad.net/~g2p/+archive/storage/
My partition layout us as follows:
sda 8:0 0 223.6G 0 disk
├─sda1 8:1 0 499M 0 part
│ └─md1 9:1 0 499M 0 raid1 /boot
├─sda2 8:2 0 20G 0 part
│ └─md2 9:2 0 20G 0 raid1 /
├─sda3 8:3 0 11.7G 0 part
│ └─md3 9:3 0 11.6G 0 raid1
└─sda4 8:4 0 191.5G 0 part
└─md4 9:4 0 191.3G 0 raid1
sdb 8:16 0 223.6G 0 disk
├─sdb1 8:17 0 499M 0 part
│ └─md1 9:1 0 499M 0 raid1 /boot
├─sdb2 8:18 0 20G 0 part
│ └─md2 9:2 0 20G 0 raid1 /
├─sdb3 8:19 0 11.7G 0 part
│ └─md3 9:3 0 11.6G 0 raid1
└─sdb4 8:20 0 191.5G 0 part
└─md4 9:4 0 191.3G 0 raid1
sdc 8:32 0 1.8T 0 disk
└─sdc1 8:33 0 1.8T 0 part
└─md5 9:5 0 1.8T 0 raid1
sdd 8:48 0 1.8T 0 disk
└─sdd1 8:49 0 1.8T 0 part
└─md5 9:5 0 1.8T 0 raid1
I intend to use /dev/md5 as my backing device, and /dev/md4 as my cache device.
To create the backing device, I've done the following:
make-bcache -B /dev/md5
UUID: 4264d526-cd5e-43d9-a969-3eb2bf81aa91
Set UUID: e4bee610-da76-49ff-8636-08b80005a826
version: 1
block_size: 1
data_offset: 16
Similarly, to create the caching device:
make-bcache -C /dev/md4
UUID: 8c425d36-c4a9-4e0b-9c78-a633afabf359
Set UUID: 5f807648-f510-4315-8665-e650773accf1
version: 0
nbuckets: 391811
block_size: 1
bucket_size: 1024
nr_in_set: 1
nr_this_dev: 0
first_bucket: 1
Attach the backing device:
echo 5f807648-f510-4315-8665-e650773accf1 > /sys/block/bcache0/bcache/attach
Confirm the bcache0 device appears in lsblk (it does), and check the bcache state:
cat /sys/block/bcache0/bcache/state
clean
Set writeback mode:
echo writeback > /sys/block/bcache0/bcache/cache_mode
Create LVM physical volume:
pvcreate /dev/bcache0
Device /dev/bcache0 not found (or ignored by filtering).
Even after a reboot to force a re-read, I still get this same error. Anybody see what I'm doing wrong?
