通過libvirt使用ceph塊設備
1. 創建存儲池
[root@ceph1 ~]# ceph osd pool create libvirt-pool 128 128
查看剛剛創建的存儲池：
[root@ceph1 ~]# ceph osd lspools
0 rbd,1 .rgw.root,2 default.rgw.control,3 default.rgw.meta,4 default.rgw.log,5 default.rgw.buckets.index,6 default.rgw.buckets.data,7 default.rgw.buckets.non-ec,8 libvirt-pool,
2. 創建ceph用戶client.libvirt，權限限制到存儲池libvirt-pool
[root@ceph1 ~]# ceph auth get-or-create client.libvirt mon 'allow r' osd 'allow class-read object_prefix rbd_children, allow rwx pool=libvirt-pool'
驗證：
[root@ceph1 ~]# ceph auth list
...
client.libvirt
key: AQBblU1b9FECCRAA4tW8qaBYtxTsDlaNJybZSQ==
caps: [mon] allow r
caps: [osd] allow class-read object_prefix rbd_children, allow rwx pool=libvirt-pool
...
3. 把虛擬機鏡像文件centos6864.qcow2.img導入存儲池libvirt-pool中
[root@ceph1 ~]# qemu-img convert -f qcow2 -O raw centos6864.qcow2.img rbd:libvirt-pool/centos6864.qcow2.img
驗證：
[root@ceph1 ~]# rbd -p libvirt-pool ls
centos6864.qcow2.img
4. 在libvirt中配置ceph認證需要的密鑰
a. 定義密鑰
[root@localhost ~]# cat > secret.xml <<EOF
<secret ephemeral='no' private='no'>
<usage type='ceph'>
<name>client.libvirt secret</name>
</usage>
</secret>
virsh secret-define --file secret.xml
b. 獲取密鑰uuid
[root@localhost ~]# virsh secret-list
UUID Usage
--------------------------------------------------------------------------------
fdcb5967-d3e5-4618-98f5-5919a723e414 ceph client.libvirt secret
c. 設置密鑰的值
virsh secret-set-value --secret fdcb5967-d3e5-4618-98f5-5919a723e414 --base64 AQBblU1b9FECCRAA4tW8qaBYtxTsDlaNJybZSQ==
其中“AQBblU1b9FECCRAA4tW8qaBYtxTsDlaNJybZSQ==”是從上面ceph auth list的client.libvirt的key字段中得到的
5. 修改虛擬機xml文件的disk部分
[root@localhost ~]# virsh edit test
...
<disk type='network' device='disk'>
<driver name='qemu'/>
<auth username='libvirt'>
<secret type='ceph' uuid='fdcb5967-d3e5-4618-98f5-5919a723e414'/>
</auth>
<source protocol='rbd' name='libvirt-pool/centos6864.qcow2.img'>
<host name='192.168.1.15' port='6789'/>
<host name='192.168.1.16' port='6789'/>
<host name='192.168.1.17' port='6789'/>
</source>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</disk>
...
其中secret的uuid就是上面創建密鑰的uuid；host配置的是ceph monitor的ip和端口，有幾個monitor就寫幾個。
6. 開啟虛擬機
[root@localhost ~]# virsh start test
通過libvirt使用ceph塊設備