Red Hat Summit Red Hat Summit지원콘솔개발자평가판 시작연락처

이 콘텐츠는 선택한 언어로 제공되지 않습니다.

Chapter 4. Removing a Node From the Overcloud

The Red Hat OpenStack Platform director (RHOSP-d) does not support the removal of a Red Hat Ceph Storage (RHCS) node automatically.

4.1. Prerequisites
링크 복사

  • Verify there will be enough CPU and RAM to service the workloads.
  • Migrate the compute workloads off of the node being removed.
  • Verify that the storage cluster has enough reserve storage capacity to maintain a status of HEALTH_OK.

4.2. Removing the Ceph OSD services from the storage cluster
링크 복사

This procedure removes the Ceph OSD services from being a member of the storage cluster.

Prerequisite

  • A healthy Ceph storage cluster.

Procedure

Do the following steps on one of the Controller/Monitor nodes, and as the root user, unless otherwise stated.

  1. Verify the health status of the Ceph storage cluster: 

    [root@controller ~]# ceph health
    Copy to Clipboard Toggle word wrap

    The health status must be HEALTH_OK before continuing on with this procedure.

    Warning

    If the ceph health command reports that the storage cluster is near full, then removing a Ceph OSD could result in exceeding or reaching the full ratio limit. This could cause data loss. If the storage cluster is near full, then contact Red Hat Support before proceeding.

  2. Determine the number of Ceph OSDs for removal: 

    [root@controller ~]# ceph osd tree
    Copy to Clipboard Toggle word wrap

    Example Output

    ID WEIGHT   TYPE NAME                        UP/DOWN REWEIGHT PRIMARY-AFFINITY
-1 52.37256 root default
-2 13.09314     host overcloud-osd-compute-3
 0  1.09109         osd.0                         up  1.00000          1.00000
 4  1.09109         osd.4                         up  1.00000          1.00000
 8  1.09109         osd.8                         up  1.00000          1.00000
12  1.09109         osd.12                        up  1.00000          1.00000
16  1.09109         osd.16                        up  1.00000          1.00000
20  1.09109         osd.20                        up  1.00000          1.00000
24  1.09109         osd.24                        up  1.00000          1.00000
28  1.09109         osd.28                        up  1.00000          1.00000
32  1.09109         osd.32                        up  1.00000          1.00000
36  1.09109         osd.36                        up  1.00000          1.00000
40  1.09109         osd.40                        up  1.00000          1.00000
44  1.09109         osd.44                        up  1.00000          1.00000
...
    Copy to Clipboard Toggle word wrap

    To view the total number of OSDs up and in: 

    [root@controller ~]# ceph osd stat
    Copy to Clipboard Toggle word wrap

    Example Output

    osdmap e173: 48 osds: 48 up, 48 in
            flags sortbitwise
    Copy to Clipboard Toggle word wrap

  3. Monitor the Ceph storage cluster from a new terminal session: 

    [root@controller ~]# ceph -w
    Copy to Clipboard Toggle word wrap

    In this terminal session, you can watch as the OSD is removed from the storage cluster. Go back to the original terminal session for the next step.

  4. Mark the OSD out: 

    ceph osd out $OSD_NUM
    Copy to Clipboard Toggle word wrap
    Replace…​

    • $OSD_NUM with the number portion of the OSD name.

      Example

      [root@controller ~]# ceph osd out 0
marked out osd.0.
      Copy to Clipboard Toggle word wrap

      Set all OSDs on the node to out.

      Note

      If scripting this step to handle multiple OSDs sequentially, then set a sleep command of at least 10 seconds in between the running of each ceph osd out command.

  5. Wait for all the placement groups to become active+clean and the storage cluster is in a HEALTH_OK state. You can watch the placement group migration from the new terminal session from step 3. This rebalancing of data can take some time to complete.

  6. Verify the health status of the Ceph storage cluster: 

    [root@controller ~]# ceph health
    Copy to Clipboard Toggle word wrap

  7. From the Compute/OSD node, and as the root user, disable and stop all OSD daemons: 

    [root@osdcompute ~]# systemctl disable ceph-osd.target
[root@osdcompute ~]# systemctl stop ceph-osd.target
    Copy to Clipboard Toggle word wrap

  8. Remove the OSD from the CRUSH map: 

    ceph osd crush remove osd.$OSD_NUM
    Copy to Clipboard Toggle word wrap
    Replace…​

    • $OSD_NUM with the number portion of the OSD name.

      Example

      [root@controller ~]# ceph osd crush remove osd.0
removed item id 0 name 'osd.0' from crush map
      Copy to Clipboard Toggle word wrap

      Note

      Removing an OSD from the CRUSH map, causes CRUSH to recompute which OSDs get the placement groups, and rebalances the data accordingly.

  9. Remove the OSD authentication key: 

    ceph auth del osd.$OSD_NUM
    Copy to Clipboard Toggle word wrap
    Replace…​

    • $OSD_NUM with the number portion of the OSD name.

      Example

      [root@controller ~]# ceph osd auth del osd.0
updated
      Copy to Clipboard Toggle word wrap

  10. Remove the OSD: 

    ceph osd rm $OSD_NUM
    Copy to Clipboard Toggle word wrap
    Replace…​

    • $OSD_NUM with the number portion of the OSD name.

      Example

      [root@controller ~]# ceph osd rm 0
removed osd.0
      Copy to Clipboard Toggle word wrap

4.3. Removing the nova compute services from the overcloud
링크 복사

This procedure removes the Nova compute services from being a member of the overcloud, and powers off the hardware.

Prerequisite

  • Migrate any running instances to another compute node in the overcloud.

Procedure

Do the following steps on the Red Hat OpenStack Platform director (RHOSP-d) node, as the stack user.

  1. Verify the status of the compute node: 

    [stack@director ~]$ nova service-list
    Copy to Clipboard Toggle word wrap

  2. Disable the compute service: 

    nova service-disable $HOST_NAME nova-compute
    Copy to Clipboard Toggle word wrap
    Replace…​

    • $HOST_NAME with the compute’s host name.

      Example

      [stack@director ~]$ nova service-disable overcloud-osd-compute-3.localdomain nova-compute
+-------------------------------------+--------------+----------+
| Host                                | Binary       | Status   |
+-------------------------------------+--------------+----------+
| overcloud-osd-compute-3.localdomain | nova-compute | disabled |
+-------------------------------------+--------------+----------+
      Copy to Clipboard Toggle word wrap

  3. Collect the Nova ID of the compute node: 

    [stack@director ~]$ openstack server list
    Copy to Clipboard Toggle word wrap

    Write down the Nova UUID, which is in the first column of the command output.

  4. Collect the OpenStack Platform name: 

    [stack@director ~]$ heat stack-list
    Copy to Clipboard Toggle word wrap

    Write down the stack_name, which is the second column of the command output.

  5. Delete the compute node by UUID from the overcloud: 

    openstack overcloud node delete --stack OSP_NAME NOVA_UUID
    Copy to Clipboard Toggle word wrap
    Replace…​
    • OSP_NAME with the `stack_name`from the previous step.

    • NOVA_UUID with the Nova UUID from the previous step.

      Example

      [stack@director ~]$ openstack overcloud node delete --stack overcloud 6b2a2e71-f9c8-4d5b-aaf8-dada97c90821
deleting nodes [u'6b2a2e71-f9c8-4d5b-aaf8-dada97c90821'] from stack overcloud
Started Mistral Workflow. Execution ID: 396f123d-df5b-4f37-b137-83d33969b52b
      Copy to Clipboard Toggle word wrap

  6. Verify that the compute node was removed from the overcloud: 

    [stack@director ~]$ openstack server list
    Copy to Clipboard Toggle word wrap

    If the compute node was successfully removed, then it will not be listed in the above command output. 

    [stack@director ~]$ nova service-list
    Copy to Clipboard Toggle word wrap

    The removed Nova compute node’s status will be disabled and down.

  7. Verify that Ironic has powered off the node: 

    [stack@director ~]$ openstack baremetal node list
    Copy to Clipboard Toggle word wrap

    The compute node’s power state and availability will be power off and available respectively. Write down the Nova compute service ID, which is the value in the first column of the above command output.

  8. Remove the compute node from the nova-compute service from the Nova scheduler: 

    nova service-delete COMPUTE_SERVICE_ID
    Copy to Clipboard Toggle word wrap
    Replace…​

    • COMPUTE_SERVICE_ID with the Nova compute service ID from the previous step.

      Example

      [stack@director ~]$ nova service-delete 145
      Copy to Clipboard Toggle word wrap

4.4. Addtional Resources
링크 복사

  • The Red Hat Ceph Storage Administration Guide.
맨 위로 이동
Red Hat logoGithubredditYoutubeTwitter

자세한 정보

평가판, 구매 및 판매

커뮤니티

Red Hat 문서 정보

Red Hat을 사용하는 고객은 신뢰할 수 있는 콘텐츠가 포함된 제품과 서비스를 통해 혁신하고 목표를 달성할 수 있습니다. 최신 업데이트를 확인하세요.

보다 포괄적 수용을 위한 오픈 소스 용어 교체

Red Hat은 코드, 문서, 웹 속성에서 문제가 있는 언어를 교체하기 위해 최선을 다하고 있습니다. 자세한 내용은 다음을 참조하세요.Red Hat 블로그.

Red Hat 소개

Red Hat은 기업이 핵심 데이터 센터에서 네트워크 에지에 이르기까지 플랫폼과 환경 전반에서 더 쉽게 작업할 수 있도록 강화된 솔루션을 제공합니다.

Theme

© 2025 Red Hat