4-安装cephadm

视频链接：安装cephadm

1. 安装cephadm，O版开始就不再支持ceph-deploy工具
> [cephadm安装](https://docs.ceph.com/en/latest/cephadm/install/#install-cephadm)
> cephadm安装前提
- Python3
- Systemd
- Podman or Docker
- Chrony or NTP
- LVM2
```shell
## 在ceph所有点上执行
# CEPH_RELEASE=17.2.6 # replace this with the active release
# curl --silent --remote-name --location https://download.ceph.com/rpm-${CEPH_RELEASE}/el9/noarch/cephadm
# chmod +x cephadm
# mv cephadm /usr/sbin/
## 执行cephadm install 会在当前节点上安装cephadm依赖相关的软件包，版本较低，所以不建议执行
# cephadm install
ERROR: Distro openeuler version 22.03 not supported
## 修改 /usr/sbin/cephadm ，在
# vi /usr/sbin/cephadm
## DISTRO_NAMES 这个字典中增加 openeuler
  7654     DISTRO_NAMES = {
  7655         'centos': ('centos', 'el'),
  7656         'rhel': ('centos', 'el'),
  7657         'scientific': ('centos', 'el'),
  7658         'rocky': ('centos', 'el'),
  7659         'openeuler': ('centos', 'el'),
  7660         'almalinux': ('centos', 'el'),
  7661         'ol': ('centos', 'el'),
  7662         'fedora': ('fedora', 'fc'),
  7663         'mariner': ('mariner', 'cm'),
  7664     }
  7665  
## 将 cephadm 文件拷贝到其他节点上  
# for i in {2..5};do scp -rp /usr/sbin/cephadm ceph0$i:/usr/sbin/;done
```
> 如果是Centos8，可直接yum源安装
````shell
# yum download cephadm
# rpm -ivh cephadm-17.2.6-0.el8.noarch.rpm
# rpm -ql cephadm-17.2.6-0.el8
/usr/sbin/cephadm
/usr/share/man/man8/cephadm.8.gz
/var/lib/cephadm
/var/lib/cephadm/.ssh
/var/lib/cephadm/.ssh/authorized_keys
````
2. 检查ceph各节点是否满足安装ceph集群，该命令需要在当前节点执行，比如要判断ceph02是否支持安装ceph集群，则在ceph02上执行
```shell
# cephadm check-host --expect-hostname ceph02
docker (/usr/bin/docker) is present
systemctl is present
lvcreate is present
Unit chronyd.service is enabled and running
Hostname "ceph02" matches what is expected.
Host looks OK

## 也可以使用以下命令检查
# cephadm check-host --expect-hostname `hostname`
```