在无人看管的断电后，面临一个重大问题，DBRB每次重新启动都会出现已连接无盘/无盘状态。
主要问题：
- dump-md 响应：发现元数据是“不干净的”
- apply-al 命令以退出代码 20 终止，消息打开（/dev/nvme0n1p1）失败：设备或资源忙
- drbd 资源配置无法独占打开。
关于环境：
这个 drbd 资源通常用作 lvm 的块存储，它被配置为 proxmox ve 5.3-8 集群的（共享 lvm）存储。在 drbd 块设备之上配置了一个 lvm，但在 drbd 主机 lvm config 上，drbd 服务下面的设备（/dev/nvme0n1p1）被过滤掉（/etc/lvm/lvm.conf 如下所示）
drbd下的设备是PCIe NVMe设备
它具有 systemctl 显示的一些额外属性：
root@pmx0:~# systemctl list-units | grep nvme
sys-devices-pci0000:00-0000:00:01.1-0000:0c:00.0-nvme-nvme0-nvme0n1-nvme0n1p1.device loaded active plugged /sys/devices/pci0000:00/0000:00:01.1/0000:0c:00.0/nvme/nvme0/nvme0n1/nvme0n1p1
sys-devices-pci0000:00-0000:00:01.1-0000:0c:00.0-nvme-nvme0-nvme0n1.device loaded active plugged /sys/devices/pci0000:00/0000:00:01.1/0000:0c:00.0/nvme/nvme0/nvme0n1
sytemctl 中列出的其他存储设备普通 SAS 磁盘看起来有些不同：
root@pmx0:~# systemctl list-units | grep sdb
sys-devices-pci0000:00-0000:00:01.0-0000:0b:00.0-host0-target0:2:1-0:2:1:0-block-sdb-sdb1.device loaded active plugged PERC_H710 1
sys-devices-pci0000:00-0000:00:01.0-0000:0b:00.0-host0-target0:2:1-0:2:1:0-block-sdb-sdb2.device loaded active plugged PERC_H710 2
sys-devices-pci0000:00-0000:00:01.0-0000:0b:00.0-host0-target0:2:1-0:2:1:0-block-sdb.device loaded active plugged PERC_H710
使用 ls 列出 NVMe /sys/devices/..：
root@pmx0:~# ls /sys/devices/pci0000:00/0000:00:01.1/0000:0c:00.0/nvme/nvme0/nvme0n1/nvme0n1p1
alignment_offset dev discard_alignment holders inflight partition power ro size start stat subsystem trace uevent
事情不是hepls：
- 再次重启无济于事
- drbd 服务重启无济于事
- drbdadm 分离/断开/附加/服务重启无济于事
- 在这些 drbd 节点上未配置 nfs-kernel-server 服务（因此无法取消配置 nfs-server）
经过一番调查：
dump-md response: Found meta data is "unclean" , please apply-al first apply-al command terminate with exit code 20 with this message: open(/dev/nvme0n1p1) failed: Device or resource busy
看来问题是我的drbd资源配置使用的这个设备（/dev/nvme0n1p1）不能独占打开。
失败的 DRBD 命令：
root@pmx0:~# drbdadm attach r0
open(/dev/nvme0n1p1) failed: Device or resource busy
Operation canceled.
Command 'drbdmeta 0 v08 /dev/nvme0n1p1 internal apply-al' terminated with exit code 20
root@pmx0:~# drbdadm apply-al r0
open(/dev/nvme0n1p1) failed: Device or resource busy
Operation canceled.
Command 'drbdmeta 0 v08 /dev/nvme0n1p1 internal apply-al' terminated with exit code 20
root@pmx0:~# drbdadm dump-md r0
open(/dev/nvme0n1p1) failed: Device or resource busy
Exclusive open failed. Do it anyways?
[need to type 'yes' to confirm] yes
Found meta data is "unclean", please apply-al first
Command 'drbdmeta 0 v08 /dev/nvme0n1p1 internal dump-md' terminated with exit code 255
DRBD 服务状态/命令：
root@pmx0:~# drbd-overview
0:r0/0 Connected Secondary/Secondary Diskless/Diskless
root@pmx0:~# drbdadm dstate r0
Diskless/Diskless
root@pmx0:~# drbdadm disconnect r0
root@pmx0:~# drbd-overview
0:r0/0 . . .
root@pmx0:~# drbdadm detach r0
root@pmx0:~# drbd-overview
0:r0/0 . . .
尝试重新附加资源 r0：
root@pmx0:~# drbdadm attach r0
open(/dev/nvme0n1p1) failed: Device or resource busy
Operation canceled.
Command 'drbdmeta 0 v08 /dev/nvme0n1p1 internal apply-al' terminated with exit code 20
root@pmx0:~# drbdadm apply-al r0
open(/dev/nvme0n1p1) failed: Device or resource busy
Operation canceled.
Command 'drbdmeta 0 v08 /dev/nvme0n1p1 internal apply-al' terminated with exit code 20
lsof，定影器零输出：
root@pmx0:~# lsof /dev/nvme0n1p1
root@pmx0:~# fuser /dev/nvme0n1p1
root@pmx0:~# fuser /dev/nvme0n1
root@pmx0:~# lsof /dev/nvme0n1
资源磁盘分区和 LVM 配置：
root@pmx0:~# fdisk -l /dev/nvme0n1
Disk /dev/nvme0n1: 1.9 TiB, 2048408248320 bytes, 4000797360 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x59762e31
Device Boot Start End Sectors Size Id Type
/dev/nvme0n1p1 2048 3825207295 3825205248 1.8T 83 Linux
root@pmx0:~# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb2 pve lvm2 a-- 135.62g 16.00g
root@pmx0:~# vgs
VG #PV #LV #SN Attr VSize VFree
pve 1 3 0 wz--n- 135.62g 16.00g
root@pmx0:~# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
data pve twi-a-tz-- 75.87g 0.00 0.04
root pve -wi-ao---- 33.75g
swap pve -wi-ao---- 8.00g
root@pmx0:~# vi /etc/lvm/lvm.conf
root@pmx0:~# cat /etc/lvm/lvm.conf | grep nvm
filter = [ "r|/dev/nvme0n1p1|", "a|/dev/sdb|", "a|sd.*|", "a|drbd.*|", "r|.*|" ]
DRBD 资源配置：
root@pmx0:~# cat /etc/drbd.d/r0.res
resource r0 {
protocol C;
startup {
wfc-timeout 0; # non-zero wfc-timeout can be dangerous (http://forum.proxmox.com/threads/3465-Is-it-safe-to-use-wfc-timeout-in-DRBD-configuration)
degr-wfc-timeout 300;
become-primary-on both;
}
net {
cram-hmac-alg sha1;
shared-secret "*********";
allow-two-primaries;
after-sb-0pri discard-zero-changes;
after-sb-1pri discard-secondary;
after-sb-2pri disconnect;
#data-integrity-alg crc32c; # has to be enabled only for test and disabled for production use (check man drbd.conf, section "NOTES ON DATA INTEGRITY")
}
on pmx0 {
device /dev/drbd0;
disk /dev/nvme0n1p1;
address 10.0.20.15:7788;
meta-disk internal;
}
on pmx1 {
device /dev/drbd0;
disk /dev/nvme0n1p1;
address 10.0.20.16:7788;
meta-disk internal;
}
disk {
# no-disk-barrier and no-disk-flushes should be applied only to systems with non-volatile (battery backed) controller caches.
# Follow links for more information:
# http://www.drbd.org/users-guide-8.3/s-throughput-tuning.html#s-tune-disable-barriers
# http://www.drbd.org/users-guide/s-throughput-tuning.html#s-tune-disable-barriers
no-disk-barrier;
no-disk-flushes;
}
}
其他节点：
root@pmx1:~# drbd-overview
0:r0/0 Connected Secondary/Secondary Diskless/Diskless
依此类推，每个命令响应和配置都显示与上面的节点 pmx0 相同...
Debian 和 DRBD 版本：
root@pmx0:~# uname -a
Linux pmx0 4.15.18-10-pve #1 SMP PVE 4.15.18-32 (Sat, 19 Jan 2019 10:09:37 +0100) x86_64 GNU/Linux
root@pmx0:~# cat /etc/debian_version
9.8
root@pmx0:~# dpkg --list| grep drbd
ii drbd-utils 8.9.10-2 amd64 RAID 1 over TCP/IP for Linux (user utilities)
root@pmx0:~# lsmod | grep drbd
drbd 364544 1
lru_cache 16384 1 drbd
libcrc32c 16384 2 dm_persistent_data,drbd
root@pmx0:~# modinfo drbd
filename: /lib/modules/4.15.18-10-pve/kernel/drivers/block/drbd/drbd.ko
alias: block-major-147-*
license: GPL
version: 8.4.10
description: drbd - Distributed Replicated Block Device v8.4.10
author: Philipp Reisner <phil@linbit.com>, Lars Ellenberg <lars@linbit.com>
srcversion: 9A7FB947BDAB6A2C83BA0D4
depends: lru_cache,libcrc32c
retpoline: Y
intree: Y
name: drbd
vermagic: 4.15.18-10-pve SMP mod_unload modversions
parm: allow_oos:DONT USE! (bool)
parm: disable_sendpage:bool
parm: proc_details:int
parm: minor_count:Approximate number of drbd devices (1-255) (uint)
parm: usermode_helper:string
坐骑：
root@pmx0:~# cat /proc/mounts
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,relatime 0 0
udev /dev devtmpfs rw,nosuid,relatime,size=24679656k,nr_inodes=6169914,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,nosuid,noexec,relatime,size=4940140k,mode=755 0 0
/dev/mapper/pve-root / ext4 rw,relatime,errors=remount-ro,data=ordered 0 0
securityfs /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
tmpfs /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
tmpfs /sys/fs/cgroup tmpfs ro,nosuid,nodev,noexec,mode=755 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd 0 0
pstore /sys/fs/pstore pstore rw,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/net_cls,net_prio cgroup rw,nosuid,nodev,noexec,relatime,net_cls,net_prio 0 0
cgroup /sys/fs/cgroup/hugetlb cgroup rw,nosuid,nodev,noexec,relatime,hugetlb 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset 0 0
cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0
cgroup /sys/fs/cgroup/memory cgroup rw,nosuid,nodev,noexec,relatime,memory 0 0
cgroup /sys/fs/cgroup/rdma cgroup rw,nosuid,nodev,noexec,relatime,rdma 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0
cgroup /sys/fs/cgroup/pids cgroup rw,nosuid,nodev,noexec,relatime,pids 0 0
cgroup /sys/fs/cgroup/perf_event cgroup rw,nosuid,nodev,noexec,relatime,perf_event 0 0
systemd-1 /proc/sys/fs/binfmt_misc autofs rw,relatime,fd=39,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=20879 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
hugetlbfs /dev/hugepages hugetlbfs rw,relatime,pagesize=2M 0 0
mqueue /dev/mqueue mqueue rw,relatime 0 0
sunrpc /run/rpc_pipefs rpc_pipefs rw,relatime 0 0
configfs /sys/kernel/config configfs rw,relatime 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
/dev/sda1 /mnt/intelSSD700G ext3 rw,relatime,errors=remount-ro,data=ordered 0 0
lxcfs /var/lib/lxcfs fuse.lxcfs rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other 0 0
/dev/fuse /etc/pve fuse rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other 0 0
10.0.0.15:/samba/shp /mnt/pve/bckNFS nfs rw,relatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.0.0.15,mountvers=3,mountport=42772,mountproto=udp,local_lock=none,addr=10.0.0.15 0 0