use opencas to acclerate my ceph OSD

[sp900409]

Question

I am trying use opencas to accelerate my ceph OSD, I get everything compiled and config running, if I use mount /dev/cas1-1 it would be ok and fine to use. The cache device and core device are all up and running. however when i trying to setup Ceph OSD, it show unknown device type and not able to move on.
the error message is list below:
root@node4:~# pvck /dev/cas1-1
Cannot use /dev/cas1-1: device type is unknown.

Look LVM does recognized /dev/cas1-1 as am physical volume.
I also trying below LVM command, it still has the error.
pvck /dev/cas1-1
Cannot use /dev/cas1-1: device type is unknown.

lsblk success recognized it as am disk.
root@node4:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 1.7T 0 disk
└─ceph--6dbc380b--8a75--48af--8a7f--553093aaf770-osd--block--12808c31--c2a2--40ef--8fc8--722516fd5ee3
253:5 0 1.7T 0 lvm
sdb 8:16 0 1.7T 0 disk
sdc 8:32 0 1.8T 0 disk
└─ceph--e1cc3d00--fa38--48f7--bd6e--ad1ba411a078-osd--block--e41e133f--07b5--46be--8723--9f028ee2dfae
253:8 0 1.8T 0 lvm
sdd 8:48 0 1.8T 0 disk
└─cas1-1 252:0 0 1.8T 0 disk
sde 8:64 0 931.5G 0 disk
├─sde1 8:65 0 1007K 0 part
├─sde2 8:66 0 512M 0 part
└─sde3 8:67 0 931G 0 part
├─pve-swap 253:0 0 8G 0 lvm [SWAP]
├─pve-root 253:1 0 96G 0 lvm /
├─pve-data_tmeta 253:2 0 8.1G 0 lvm
│ └─pve-data 253:4 0 794.8G 0 lvm
└─pve-data_tdata 253:3 0 794.8G 0 lvm
└─pve-data 253:4 0 794.8G 0 lvm
nvme0n1 259:0 0 1.5T 0 disk
└─ceph--8c848143--5791--4d00--9f8e--15a839b1f656-osd--db--88459ca3--a0d5--4292--ba02--415ecda8a77f
253:7 0 186.3G 0 lvm

Anyone has idea to figure it out would be appreciated. Thanks in advance.

Motivation

Your Environment

• OpenCAS version (commit hash or tag):
• +=========================+=====================+
  | Name | Version |
  +=========================+=====================+
  | CAS Cache Kernel Module | 22.12.0.0843.master |
  | CAS CLI Utility | 22.12.0.0843.master |
  +=========================+=====================+
• Operating System:
• PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
  NAME="Debian GNU/Linux"
  VERSION_ID="11"
  VERSION="11 (bullseye)"
  VERSION_CODENAME=bullseye
• Kernel version: Linux node4 5.15.107-1-pve Add README and LICENSE files #1 SMP PVE 5.15.107-1 (2023-04-20T10:05Z) x86_64 GNU/Linux
• Cache device type (NAND/Optane/other): Cache on Samsung 1643a on top of Core device on Crucial SSD
• Core device type (HDD/SSD/other):
• Cache configuration:
• • Cache mode: (default: wt)
    root@node4:~# casadm -P -i 1
    Cache Id 1
    Cache Size 463960726 [4KiB Blocks] / 1769.87 [GiB]
    Cache Device /dev/sdb
    Exported Object -
    Core Devices 1
    Inactive Core Devices 0
    Write Policy wb
    Cleaning Policy alru
    Promotion Policy always
    Cache line size 4 [KiB]
    Metadata Memory Footprint 20.3 [GiB]
    Dirty for 0 [s] / Cache clean
    Status Running
• • Cache line size: (default: 4)
• • Promotion policy: (default: always)
• • Cleaning policy: (default: alru)
• • Sequential cutoff policy: (default: full)
• Other (e.g. lsblk, casadm -P, casadm -L)

[jfckm]

Hi @sp900409,

Thanks for your report. LVM has to be properly configured to recognize CAS device as an acceptable block device. You can find more information about that here. Let me know if it helped!