Redhat Cluster (Pacemaker/Corosync): DLM Not Starting

dlmredhatrhel7

I need help regarding my cluster error:

[root@db2]# pcs status
Cluster name: oracluster
Last updated: Mon Feb 22 16:00:12 2016
Last change: Mon Feb 22 15:45:14 2016
Stack: corosync
Current DC: db2 (2) - partition with quorum
Version: 1.1.12-a14efad
2 Nodes configured
5 Resources configured


Online: [ db1 db2 ]

Full list of resources:

 ClusterVIP (ocf::heartbeat:IPaddr2):   Started db2
 Clone Set: dlm-clone [dlm]
     Stopped: [ db1 db2 ]
 Clone Set: clvmd-clone [clvmd]
     Stopped: [ db1 db2 ]

Failed actions:
    dlm_start_0 on db2 'not configured' (6): call=18, status=complete, exit-reason='none', last-rc-change='Mon Feb 22 15:57:04 2016', queued=0ms, exec=34ms


PCSD Status:
  db1: Online
  db2: Online

Daemon Status:
  corosync: active/disabled
  pacemaker: active/disabled
  pcsd: active/enabled

Details:

I have 2 nodes (db1, db2) with shared storage (SAN). Both servers are in RHEL7.1. Now I want to add the storage as a resource. According to RHEL documentation DLM and CLVMD should be added also as a resource. I discovered that the error will disapper when STONITH is enabled, but still DLM is not starting. The log says it needs Fencing Device to be configured, which I don't have right now.

Any work around for this? Do we have a way to disable the fence mechanism and still make the cluster work? Thank you so much in advance!

Best Answer

you said that you have san storage, then you create a partion for fencing and use it as scsi stonith, il will solve your problem, like this exemple:

pcs stonith create scsi-stonith-device fence_scsi devices=/dev/mapper/fence pcmk_monitor_action=metadata pcmk_reboot_action=off pcmk_host_list="node1 node2" meta provides=unfencing

and don't forget to enable stonith with pcs property set stonith-enabled=true

Related Solutions

Configure LVM resource on Redhat 7.4 cluster using pacemaker

I have Fix my issue with the following step to create a LVM resource. sdb is my shared disk I represent from the iscsi hosts.

[root@rhel-1 ~]# lsblk
NAME          MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda             8:0    0   20G  0 disk
├─sda1          8:1    0    1G  0 part /boot
└─sda2          8:2    0   19G  0 part
  ├─rhel-root 253:0    0   17G  0 lvm  /
  └─rhel-swap 253:1    0    2G  0 lvm  [SWAP]
sdb             8:16   0   50G  0 disk
sr0            11:0    1  3.8G  0 rom  /mnt

Then I created a new partition for sdb.

[root@rhel-1 ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xf8a80986.

Command (m for help): p

Disk /dev/sdb: 53.7 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 33550336 bytes
Disk label type: dos
Disk identifier: 0xf8a80986

   Device Boot      Start         End      Blocks   Id  System

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1):
First sector (65528-104857599, default 65528):
Using default value 65528
Last sector, +sectors or +size{K,M,G} (65528-104857599, default 104857599):
Using default value 104857599
Partition 1 of type Linux and of size 50 GiB is set

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

[root@rhel-1 ~]# lsblk
NAME          MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda             8:0    0   20G  0 disk
├─sda1          8:1    0    1G  0 part /boot
└─sda2          8:2    0   19G  0 part
  ├─rhel-root 253:0    0   17G  0 lvm  /
  └─rhel-swap 253:1    0    2G  0 lvm  [SWAP]
sdb             8:16   0   50G  0 disk
└─sdb1          8:17   0   50G  0 part
sr0            11:0    1  3.8G  0 rom  /mnt

Then I created physical volume, volume group and logical volume.

[root@rhel-1 ~]# pvcreate /dev/sdb1
  Physical volume "/dev/sdb1" successfully created.
[root@rhel-1 ~]# vgcreate cluster_vg /dev/sdb1
  Volume group "cluster_vg" successfully created
[root@rhel-1 ~]# lvcreate -L 40G -n cluster_lv cluster_vg
  Logical volume "cluster_lv" created.

Create an ext4 file system on the logical volume cluster_lv.

[root@rhel-1 ~]# mkfs.ext4 /dev/mapper/cluster_vg-cluster_lv
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=8191 blocks
2621440 inodes, 10485760 blocks
524288 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2157969408
320 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632,   2654208, 4096000, 7962624

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

After that I need to make an Exclusive activation for Volume group in a cluster, but before that I need to ensure that locking_type is set to 1 and use_lvmetad is set to 0 in the /etc/lvm/lvm.conf file. I use the following command to make the changes on lvm.conf file to apply on both nodes.

[root@rhel-1 ~]# lvmconf --enable-halvm --services --startstopservices
Warning: Stopping lvm2-lvmetad.service, but it can still be activated by lvm2-lvmetad.socket
Removed symlink /etc/systemd/system/sysinit.target.wants/lvm2-lvmetad.socket.

After that I need to make sure to add the volume groups other than my cluster vg as entries to volume_list in the /etc/lvm/lvm.conf. I have made this changes on my both nodes.

[root@rhel-1 ~]# grep "volume_list = " /etc/lvm/lvm.conf
        # volume_list = [ "vg1", "vg2/lvol1", "@tag1", "@*" ]
        volume_list = [ "rhel" ]
        # auto_activation_volume_list = [ "vg1", "vg2/lvol1", "@tag1", "@*" ]
        # read_only_volume_list = [ "vg1", "vg2/lvol1", "@tag1", "@*" ]

Rebuild the initramfs boot image to guarantee that the boot image will not try to activate a volume group controlled by the cluster. Also reboot is required after rebuild the initramfs.

[root@rhel-1 ~]# dracut -f -v
[root@rhel-1 ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
[root@rhel-1 ~]# init 6

Create the LVM resource

[root@rhel-1 ~]# pcs resource create db2inst1_lvm LVM volgrpname=cluster_vg exclusive=true
Assumed agent name 'ocf:heartbeat:LVM' (deduced from 'LVM')

pcs status

[root@rhel-1 ~]# pcs status
Cluster name: juriscluster
Stack: corosync
Current DC: rhel-1 (version 1.1.16-12.el7_4.8-94ff4df) - partition with quorum
Last updated: Thu Mar 15 14:27:16 2018
Last change: Thu Mar 15 14:14:33 2018 by root via cibadmin on rhel-1

2 nodes configured
2 resources configured

Online: [ rhel-1 rhel-2 ]

Full list of resources:

 db2inst1_scsi  (stonith:fence_scsi):   Started rhel-1
 db2inst1_lvm   (ocf::heartbeat:LVM):   Started rhel-2

Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

Best Answer

Related Solutions

Configure LVM resource on Redhat 7.4 cluster using pacemaker

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