SUSE Support

Here When You Need Us

How to monitor LVM with internal dmraid

This document (7017850) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 12 Service Pack 1 (SLES 12 SP1)

Situation

Getting a status on the monitored devices  via "systemctl status lvm2-monitor" will only show devices present at the start of lvm2-monitor.service.
Monitoring is essential for automatic repair of dmraid enabled LV-mirrors.

e.g.

Creating a new LVM ( with dm-raid ):

sles12sp1-node1:~ # vgcreate MIRROR /dev/sdc /dev/sdd
  Volume group "MIRROR" successfully created
sles12sp1-node1:~ # lvcreate -m1 -n lvo1 -l 100%VG MIRROR
  Logical volume "lvo1" created.
sles12sp1-node1:~ # systemctl status lvm2-monitor
lvm2-monitor.service - Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling
   Loaded: loaded (/usr/lib/systemd/system/lvm2-monitor.service; enabled)
   Active: active (exited) since Fr 2016-07-15 14:46:30 CEST; 3min 10s ago
     Docs: man:dmeventd(8)
           man:lvcreate(8)
           man:lvchange(8)
           man:vgchange(8)
  Process: 2510 ExecStop=/sbin/lvm vgchange --monitor n --ignoreskippedcluster (code=exited, status=0/SUCCESS)
  Process: 2513 ExecStart=/sbin/lvm vgchange --monitor y --ignoreskippedcluster (code=exited, status=0/SUCCESS)
 Main PID: 2513 (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/lvm2-monitor.service

Jul 15 14:46:30 sles12sp1-node1 lvm[2513]: 1 logical volume(s) in volume group "md-raid" monitored
Jul 15 14:46:30 sles12sp1-node1 systemd[1]: Started Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling.

The newly created volume does not seem to be monitored.

Resolution

"systemctl status lvm2-monitor" is not the correct tool for the job. Use dmevent_tool instead.

sles12sp1-node1:~ # dmevent_tool -mr
Device Name: MIRROR-lvo1
    Registered DSO:   libdevmapper-event-lvm2raid.so
    UUID:             LVM-cqN9ACOPGJxHCL8I4KIZDbUZRQvWRgTYHrUgzZW1uVhc0G560lkyp2mLkeROSjI7
    Status:           Active
    Major Device #:   253
    Minor Device #:   5
    Read-only Device: No
    Error Events:     1


Cause

The service file lvm2-monitor simply starts monitoring with the command line "vgchange --monitor y ...", but has no way to show
which volumes are monitored, except volumes present at the start of the service. 

Additional Information

To make monitoring working the lvm2-lvmetad and lvm2-monitor services have to be enabled, furthermore "use_lvmetad=1" in /etc/lvm/lvm.conf ( default in SLES12 SP1 ) has to be set.

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.

  • Document ID:7017850
  • Creation Date: 15-Jul-2016
  • Modified Date:03-Mar-2020
    • SUSE Linux Enterprise Server
    • SUSE Linux Enterprise Server for SAP Applications

< Back to Support Search

For questions or concerns with the SUSE Knowledgebase please contact: tidfeedback[at]suse.com

tick icon

SUSE Support Forums

Get your questions answered by experienced Sys Ops or interact with other SUSE community experts.

tick icon

Support Resources

Learn how to get the most from the technical support you receive with your SUSE Subscription, Premium Support, Academic Program, or Partner Program.

tick icon

Open an Incident

Open an incident with SUSE Technical Support, manage your subscriptions, download patches, or manage user access.