Chapter 7. Known issues

This section documents known issues found in this release of Red Hat Ceph Storage.

7.1. The ceph-ansible Utility

Red Hat Ceph Storage installation on Red Hat OpenStack Platform fails

The ceph-ansible utility becomes unresponsive when attempting to install Red Hat Ceph Storage together with the Red Hat OpenStack Platform 16, and it returns an error similar to the following one:

'Error: unable to exec into ceph-mon-dcn1-computehci1-2: no container with name or ID ceph-mon-dcn1-computehci1-2 found: no such container'

To work around this issue, update the following part of the handler_osds.yml file, located in the ceph-ansible/roles/ceph-handler/tasks/ directory:

- name: unset noup flag
  command: "{{ container_exec_cmd | default('') }} ceph --cluster {{ cluster }} osd unset noup"
  delegate_to: "{{ groups[mon_group_name][0] }}"
  changed_when: False


- name: unset noup flag
  command: "{{ hostvars[groups[mon_group_name][0]]['container_exec_cmd'] | default('') }} ceph --cluster {{ cluster }} osd unset noup"
  delegate_to: "{{ groups[mon_group_name][0] }}"
  changed_when: False

And start the installation process again.


Ansible does not unset the norebalance flag after it completes

The rolling-update.yml Ansible playbook does not unset the norebalance flag after it completes. To work around this issue, unset the flag manually.


Ansible fails to upgrade a multisite Ceph Object Gateway when the Dashboard is enabled

When the Red Hat Ceph Storage Dashboard is enabled, an attempt to use Ansible to upgrade to a further version of Red Hat Ceph Storage fails when trying to upgrade the secondary Ceph Object Gateway site in a multisite setup. This bug does not occur on the primary site or if the Dashboard is not enabled.


7.2. Ceph Management Dashboard

The Dashboard does not show correct values for certain configuration options

Both, the Red Hat Ceph Storage Dashboard and the underlying ceph config show command do not return the current values for certain configuration options, such as fsid. This is probably because certain core options that are not meant for further modification after deploying a cluster are not updated and a default value is used. As a result, the Dashboard does not show correct values for certain configuration options.

(BZ#1765493, BZ#1772310)

NFS Ganesha in Dashboard

The Red Hat Ceph Storage Dashboard currently does not support managing NFS Ganesha.


Dashboard does not support email verification

The Red Hat Ceph Storage Dashboard does not support any email verification when changing a users password. This behavior is intentional, because the Dashboard supports Single Sign-On (SSO) and this feature can be delegated to the SSO provider.


The OSD histogram graph for read and write operations is not clear

The Red Hat Ceph Storage Dashboard does not display any numbers or description in the OSD histogram graph for read and write operations, and therefore the graph is not clear.


Dashboard returns an error when a ceph-mgr module is enabled from the ceph CLI

When enabling a Ceph Manager (ceph-mgr) module, such as telemetry, from the ceph CLI, the Red Hat Ceph Storage Dashboard displays the following error message:

0 - Unknown Error

In addition, the Dashboard does not mark the module as enabled, until the Refresh button is clicked.


The Dashboard allows modifying the LUN ID and WWN, which can lead to data corruption

The Red Hat Ceph Storage Dashboard allows you to modify the LUN ID and its World Wide Name (WWN), which is not required after creating the LUN. Moreover, editing these parameters can be dangerous for certain initiators that do not fully support this feature by default. Consequently, editing these parameters after creating them can lead to data corruption. To avoid this, do not modify the LUN ID and WWN in the Dashboard.


The Dashboard does not provide correct Ceph iSCSI error messages

If the Ceph iSCSI returns an error, for example the HTTP "400" code when trying to delete an iSCSI target while a user is logged in, the Red Hat Ceph Storage Dashboard does not forward that error code and message to the Dashboard user using the pop-up notifications, but displays a generic "500 Internal Server Error". Consequently, the message that the Dashboard provides is not informative and even misleading; an expected behavior ("users cannot delete a busy resource") is perceived as an operational failure ("internal server error"). To work around this issue, see the Dashboard logs.


The Dashboard requires to disable iptables rules

The Red Hat Ceph Storage Dashboard is unable to perform any iSCSI operations, such as creating a gateway, unless all iptables rules are manually disabled on the Ceph iSCSI node. To do so, use the following command as root or the sudo user:

# iptables -F

Note that after a reboot, the rules are enabled again. Either disable them again or delete them permanently.


7.3. Packages

Current version of Grafana causes certain bugs in the Dashboard

Red Hat Ceph Storage 4 uses the Grafana version 5.2.4. This version causes the following bugs in the Red Hat Ceph Storage Dashboard:

  • When navigating to Pools > Overall Performance, Grafana returns the following error:

    TypeError: l.c[t.type] is undefined
  • When viewing a pool’s performance details (Pools > select a pool from the list > Performance Details) the Grafana bar is displayed along with other graphs and values, but it should not be there.

These bugs will be fixed after rebasing to a newer Grafana version in a future release of Red Hat Ceph Storage.

(BZ#1786107, BZ#1762197, BZ#1765536)

7.4. Red Hat Enterprise Linux

Ansible cannot start NFS Ganesha if SELinux is in enforcing mode

When using SELinux in enforcing mode on Red Hat Enterprise Linux 8.1, the ceph-ansible utility fails to start the NFS Ganesha service because SELinux policy currently does not allow creating a directory required for NFS Ganesha.

(BZ#1794027, BZ#1796160)