RBD的块设备的镜像快照实战指南

目录

• 一.RBD的块设备的镜像快照实战案例
  • 1.创建测试的镜像
  • 2.客户端添加映射并挂载设备写入测试数据
  • 3.在ceph服务端创建快照
  • 4.客户端删除挂载的块设备内的数据
  • 5.客户端删除映射前在服务端查看块设备镜像是否被锁住，注意LOCK字段是否有"excl"属性
  • 6.客户端取消块设备映射，如果不这样做，就无法释放锁
  • 7.客户端删除映射后在服务端查看镜像是否被锁住，注意LOCK字段是否有"excl"属性
  • 8.基于之前的快照信息恢复数据
  • 9.随机找一个客户端重新挂载块设备文件，验证数据是否找回
  • 10.删除快照
• 二.RBD的块设备的快照数量限制
  • 1 创建指定数量的快照
  • 2 清空快照数量限制

一.RBD的块设备的镜像快照实战案例

1.创建测试的镜像

[root@ceph141 ~]# rbd create -s 2G yinzhengjie-rbd/rbd-snap --image-feature layering,exclusive-lock
[root@ceph141 ~]# 
[root@ceph141 ~]# rbd info yinzhengjie-rbd/rbd-snap  | grep '\sfeatures'
	features: layering, exclusive-lock
[root@ceph141 ~]# 

2.客户端添加映射并挂载设备写入测试数据

[root@ceph141 ~]# rbd map yinzhengjie-rbd/rbd-snap
/dev/rbd0
[root@ceph141 ~]# 
[root@ceph141 ~]# mkfs.xfs /dev/rbd0 
meta-data=/dev/rbd0              isize=512    agcount=8, agsize=65536 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=1024   swidth=1024 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=8 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@ceph141 ~]# 
[root@ceph141 ~]# mount /dev/rbd0 /mnt/
[root@ceph141 ~]# 
[root@ceph141 ~]# df -h | grep mnt
/dev/rbd0                2.0G   33M  2.0G   2% /mnt
[root@ceph141 ~]# 
[root@ceph141 ~]# cp /etc/os-release /mnt/
[root@ceph141 ~]# 
[root@ceph141 ~]# ll /mnt/
total 4
-rw-r--r-- 1 root root 393 Feb  1 16:20 os-release
[root@ceph141 ~]# 

3.在ceph服务端创建快照

	1 为指定块设备创建快照
[root@ceph143 ~]# rbd info yinzhengjie-rbd/rbd-snap | grep snapshot_count
	snapshot_count: 0
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-rbd-v1-20240201
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd info yinzhengjie-rbd/rbd-snap | grep snapshot_count
	snapshot_count: 1
[root@ceph143 ~]# 
[root@ceph143 ~]# 

	2 查看指定块设备快照
[root@ceph143 ~]# rbd snap list yinzhengjie-rbd/rbd-snap 
SNAPID NAME                           SIZE  PROTECTED TIMESTAMP                
     4 yinzhengjie-snap-rbd-v1-20240201 2 GiB           Thu Feb  1 16:22:24 2024 
[root@ceph143 ~]# 

4.客户端删除挂载的块设备内的数据

[root@ceph141 ~]# ll /mnt/
total 4
-rw-r--r-- 1 root root 393 Feb  1 16:20 os-release
[root@ceph141 ~]# 
[root@ceph141 ~]# rm -f  /mnt/os-release 
[root@ceph141 ~]# 
[root@ceph141 ~]# ll /mnt/
total 0
[root@ceph141 ~]# 

5.客户端删除映射前在服务端查看块设备镜像是否被锁住，注意LOCK字段是否有"excl"属性

[root@ceph143 ~]# rbd ls yinzhengjie-rbd -l
NAME                                    SIZE  PARENT FMT PROT LOCK 
...
rbd-snap                                2 GiB          2      excl 
rbd-snap@yinzhengjie-snap-rbd-v1-20240201 2 GiB          2           
...
[root@ceph143 ~]# 

6.客户端取消块设备映射，如果不这样做，就无法释放锁

[root@ceph141 ~]# umount /mnt/  # 卸载服务
[root@ceph141 ~]# 
[root@ceph141 ~]# ll /dev/rbd*  # rbd设备的映射关系还在
brw-rw---- 1 root disk 252, 0 Feb  1 16:19 /dev/rbd0

/dev/rbd:
total 0
drwxr-xr-x 2 root root 60 Feb  1 16:18 yinzhengjie-rbd
[root@ceph141 ~]# 
[root@ceph141 ~]# rbd unmap yinzhengjie-rbd/rbd-snap  # 删除映射关系
[root@ceph141 ~]# 
[root@ceph141 ~]# ll /dev/rbd*
ls: cannot access /dev/rbd*: No such file or directory
[root@ceph141 ~]# 

7.客户端删除映射后在服务端查看镜像是否被锁住，注意LOCK字段是否有"excl"属性

[root@ceph143 ~]# rbd ls yinzhengjie-rbd -l
NAME                                    SIZE  PARENT FMT PROT LOCK 
...
rbd-snap                                2 GiB          2       
rbd-snap@yinzhengjie-snap-rbd-v1-20240201 2 GiB          2           
...
[root@ceph143 ~]# 

8.基于之前的快照信息恢复数据

[root@ceph143 ~]# rbd snap list  yinzhengjie-rbd/rbd-snap
SNAPID NAME                           SIZE  PROTECTED TIMESTAMP                
     4 yinzhengjie-snap-rbd-v1-20240201 2 GiB           Thu Feb  1 16:22:24 2024 
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap rollback yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-rbd-v1-20240201
Rolling back to snapshot: 100% complete...done.
[root@ceph143 ~]# 

9.随机找一个客户端重新挂载块设备文件，验证数据是否找回

[root@ceph142 ~]# rbd map yinzhengjie-rbd/rbd-snap
/dev/rbd0
[root@ceph142 ~]# 
[root@ceph142 ~]# mount /dev/rbd0 /mnt/
[root@ceph142 ~]# 
[root@ceph142 ~]# ll /mnt/
total 4
-rw-r--r-- 1 root root 393 Feb  1 16:20 os-release
[root@ceph142 ~]# 

10.删除快照

[root@ceph143 ~]# rbd snap list  yinzhengjie-rbd/rbd-snap
SNAPID NAME                           SIZE  PROTECTED TIMESTAMP                
     4 yinzhengjie-snap-rbd-v1-20240201 2 GiB           Thu Feb  1 16:22:24 2024 
[root@ceph143 ~]# 
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap rm yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-rbd-v1-20240201
Removing snap: 100% complete...done.
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap list  yinzhengjie-rbd/rbd-snap
[root@ceph143 ~]# 

二.RBD的块设备的快照数量限制

1 创建指定数量的快照

[root@ceph143 ~]# rbd snap limit set yinzhengjie-rbd/rbd-snap --limit 3
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd info yinzhengjie-rbd/rbd-snap | egrep "snapshot_count|snapshot_limit"
	snapshot_count: 0
	snapshot_limit: 3
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v1
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v2
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v3
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v4
rbd: failed to create snapshot: (122) Disk quota exceeded
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap list  yinzhengjie-rbd/rbd-snap
SNAPID NAME              SIZE  PROTECTED TIMESTAMP                
     6 yinzhengjie-snap-v1 2 GiB           Thu Feb  1 16:33:38 2024 
     7 yinzhengjie-snap-v2 2 GiB           Thu Feb  1 16:33:42 2024 
     8 yinzhengjie-snap-v3 2 GiB           Thu Feb  1 16:33:44 2024 
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd info yinzhengjie-rbd/rbd-snap | egrep "snapshot_count|snapshot_limit"
	snapshot_count: 3
	snapshot_limit: 3
[root@ceph143 ~]# 

2 清空快照数量限制

[root@ceph143 ~]# rbd info yinzhengjie-rbd/rbd-snap | egrep "snapshot_count|snapshot_limit"
	snapshot_count: 3
	snapshot_limit: 3
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap limit clear yinzhengjie-rbd/rbd-snap
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd info yinzhengjie-rbd/rbd-snap | egrep "snapshot_count|snapshot_limit"
	snapshot_count: 3
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v4
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v5
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v6
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v7
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap create  yinzhengjie-rbd/rbd-snap --snap yinzhengjie-snap-v8
[root@ceph143 ~]# 
[root@ceph143 ~]# rbd snap list  yinzhengjie-rbd/rbd-snap
SNAPID NAME              SIZE  PROTECTED TIMESTAMP                
     6 yinzhengjie-snap-v1 2 GiB           Thu Feb  1 16:33:38 2024 
     7 yinzhengjie-snap-v2 2 GiB           Thu Feb  1 16:33:42 2024 
     8 yinzhengjie-snap-v3 2 GiB           Thu Feb  1 16:33:44 2024 
    11 yinzhengjie-snap-v4 2 GiB           Thu Feb  1 16:36:19 2024 
    12 yinzhengjie-snap-v5 2 GiB           Thu Feb  1 16:36:21 2024 
    13 yinzhengjie-snap-v6 2 GiB           Thu Feb  1 16:36:23 2024 
    14 yinzhengjie-snap-v7 2 GiB           Thu Feb  1 16:36:25 2024 
    15 yinzhengjie-snap-v8 2 GiB           Thu Feb  1 16:36:31 2024 
[root@ceph143 ~]#