TechZoneIV

  Remove OSD from Ceph Cluster Firstly check which OSD is down and want to remove from Ceph Cluster by using given command:  ceph osd tree .  Let’s say it is osd.20 which is down and want to remove. Now use the following commands a.  ceph osd out osd.20 ( If you see “ osd.20 is already out ” — it’s ok. ) b.  ceph osd down osd.20 c. Remove it:  ceph osd rm osd.20 If it says   ‘ Error EBUSY: osd.11 is still up; must be down before removal. ’ that means OSD is not dead yet. Go to the host it resides on and kill it ( systemctl stop ceph-osd@20 ), and repeat rm operation. d.  ceph osd crush rm osd.20 e. remove it authorization (it should prevent problems with ‘couldn’t add new osd with same number’):  ceph auth del osd.20 . f. Make sure it is safe to destroy the OSD: ceph osd destroy 20 --yes-i-really-mean-it g. Now check with the following command:  ceph -s  or  ceph -w h. If want to remove ceph LVM volume created on host m...

  Pre-requisites: 1. In this case, 3 mon and 3 mgr node (node01, node02, node03) will available. 2. OSD will be placed on a different node (node04 node05 node06) 3. Install Ceph to all Nodes from the Admin Node and copy keyrings to all nodes 4. For PG CALC use  https://ceph.io/pgcalc/ STEPS TO CONFIGURE CEPH CLUSTER Add a user for Ceph admin on all Nodes and Grant root privilege to Ceph admin user just added above with sudo settings. And also install required packages to all # apt  -y install openssh-server python-ceph # echo  -e ‘Defaults:ubuntu !requiretty\nubuntu ALL = (root) NOPASSWD:ALL’ | tee /etc/sudoers.d/ceph # chmod  440 /etc/sudoers.d/ceph Passwordless between each node: #ssh-keygen #ssh-copy-id node01 #ssh-copy-id node02 #ssh-copy-id node03 #ssh-copy-id node04 #ssh-copy-id node05 Install Ceph to all Nodes from Admin Node (node01). So install below commands to Admin node (node1) # sudo   apt  -y install ceph-deploy ceph-common ceph-m...