nvm: device has no media manager registered

[ckoolkarni]

Hi,

I'm trying to use the null_blk with lightnvm. (Kernel Version 4.7.0-rc2-Branch-all3-00382-g8f956a8 )

1. Remove the all the modules.
   root@pat:nvme-fabrics# modprobe -r null_blk
   root@pat:nvme-fabrics# modprobe -r gennvm
   root@pat:nvme-fabrics# modprobe -r rrpc
2. Load all the modules.
   root@pat:nvme-fabrics# modprobe gennvm
   root@pat:nvme-fabrics# modprobe rrpc
   root@pat:nvme-fabrics# modprobe null_blk use_lightnvm=1
3. Make sure moduels are loaded.
   root@pat:nvme-fabrics# lsmod | grep -e gennvm -e null_blk -e rrpc
   rrpc 24576 0
   null_blk 16384 0
   gennvm 16384 0
4. Make sure devices are created.
   root@pat:nvme-fabrics# dmesg -c
   [ 125.681973] null_blk: LightNVM only supports 4k block size
   [ 125.681981] null_blk: defaults block size to 4k
   [ 125.682645] nullb->disk_name nullb0
   [ 125.682651] nullb->disk_name nullb0
   [ 125.682659] ++ null_lnvm_id
   [ 125.682663] -- null_lnvm_id
   [ 125.682670] nvm: registered nullb0 [1/1/256/64000/4/1]
   [ 125.686255] nullb->disk_name nullb1
   [ 125.686271] nullb->disk_name nullb1
   [ 125.686282] ++ null_lnvm_id
   [ 125.686287] -- null_lnvm_id
   [ 125.686297] nvm: registered nullb1 [1/1/256/64000/4/1]
   [ 125.689221] null: module loaded
   [ 125.689230] gb 250 bs 4096 nr_devices 2 use_lightnvm TRUE queue_mode MQ
5. Get the list of available devices.
   root@pat:nvme-fabrics# lnvm devices
   Number of devices: 2
   Device Block manager Version
   nullb1 none (0,0,0)
   nullb0 none (0,0,0)
6. Try to create the device with available device list.
   root@pat:nvme-fabrics# lnvm create -d nullb0 -n mydevice -t rrpc -o 0:0
   create failed. See dmesg.
   root@pat:nvme-fabrics# dmesg -c
   [ 400.371478] nvm: device has no media manager registered.

Can someone help me to resolve this issue ?

[MatiasBjorling]

Hi,

I think the media manager initialization is missing. Does executing ./lnvm init -d nvme0n1 before lnvm create help?

Thank you