Troubleshooting OpenEBS - NDM

Unable to discover some of disks in Proxmox servers by OpenEBS

One disk is attached per Node in a 3 Node cluster in a VM Environment where CentOS is underlying OS and return only one disk. Also if the particular node is restarted, from where the disk is detected then the description of the disk attached to that node gets modified. lsblk output from one of the nodes:

Troubleshooting:

Check kubectl get blockdevice -o yaml of one of the blockdevice and check its serial number. Also ensure that serial number of other 2 blockdevices are different. NDM detect and recognise the blockdevice based on their WWN, Model, Serial and Vendor. If the blockdevice have all the parameters same then NDM cannot differentiate the blockdevice and will create only 1 BlockdDevice CR for each unique parameter. To troubleshoot the same user has to make sure the blockdevices are having at least any one unique parameter from WWN, Model, Serial and Vendor. Usually this issue faced in virtualization environment like vSphere, KVM etc.

Download custom blockdevice CR YAML file from and apply with the details of each block device. In the sample spec, ndm.io/managed: is set to false. So NDM will not manage this
blockdevice.

Note: If you are creating a block device CR manually for a custom device path, then you must add the corresponding device path under filter so that NDM will not select the particular device for BD creation. For example, if block device CR is creating for /dev/sdb manually, then you must add /dev/sdb under exclude filter of NDM configuration. See here for customizing the filter in NDM configuration.

User is having a 3 node cluster with 8 disks attached on each node. But kubectl get bd -n openebs is not detecting all the blockdevices. It is detecting some of the blockdevices from each node. This information can be obtained by running kubectl describe bd <bd_cr_name> -n openebs.

Troubleshooting:

Check kubectl get blockdevice -o yaml of one of the blockdevice and its serial number. Also, ensure that the serial number of other 2 blockdevices are different. NDM detect and recognize the blockdevice based on their WWN, Model, Serial and Vendor. If the blockdevice have all the parameters same then NDM cannot differentiate the blockdevice and will create only 1 BlockdDevice CR for each unique parameter. To troubleshoot the same user has to make sure the blockdevices are having at least anyone unique parameter from WWN, Model, Serial and Vendor. Usually this issue is faced in virtualization environment like vSphere, KVM etc. More details abour NDM daemon set functionalities can be read from .

This can be resolved this by modifying the configuration file of a VM:

  • Add a serial number by following way:

  • Restart the VM:

  • Verify the disk path for all the disks in a VM: