|
|
---
|
|
|
title: "[筆記] 用zfs的snapshot 快照功能來做 postgresql 的備份還原 / Postgresql Backup Restore Using Zfs Snapshot"
|
|
|
date: 2019-09-06T10:42:11+08:00
|
|
|
noSummary: false
|
|
|
image: "https://h.cowbay.org/images/post-default-5.jpg"
|
|
|
categories: ['筆記']
|
|
|
tags: ['postgresql','zfs','backup','restore']
|
|
|
author: "Eric Chang"
|
|
|
keywords:
|
|
|
- postgresql
|
|
|
- zfs
|
|
|
- backup
|
|
|
- restore
|
|
|
---
|
|
|
|
|
|
前面測試了用pgbarman / pgbackrest 來備份 postgresql
|
|
|
|
|
|
這次改從system file level 來下手
|
|
|
|
|
|
採用zfs 的快照來備份、還原postgresql 資料庫
|
|
|
|
|
|
|
|
|
<!--more-->
|
|
|
### 建立測試資料庫、TABLE、snapshot
|
|
|
|
|
|
#### 資料庫現況
|
|
|
只有系統預設的DB，沒有其他多的東西
|
|
|
```
|
|
|
postgres@hqdc034:~$ psql -c '\l'
|
|
|
List of databases
|
|
|
Name | Owner | Encoding | Collate | Ctype | Access privileges
|
|
|
-----------+----------+----------+-------------+-------------+-----------------------
|
|
|
postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
|
|
|
template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
|
|
|
| | | | | postgres=CTc/postgres
|
|
|
template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
|
|
|
| | | | | postgres=CTc/postgres
|
|
|
(3 rows)
|
|
|
|
|
|
postgres@hqdc034:~$ du -sh /zp/database/10/main/
|
|
|
232M /zp/database/10/main/
|
|
|
```
|
|
|
|
|
|
#### 建立第一次的快照
|
|
|
```
|
|
|
2019-09-06 09:03:46 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
no datasets available
|
|
|
2019-09-06 09:03:53 [changch@hqdc034 ~]$ sudo zfs snapshot zp/database@init_db_no_demo
|
|
|
2019-09-06 09:04:09 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 0 - 231M -
|
|
|
2019-09-06 09:04:15 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
|
|
|
#### 建立、倒回測試資料庫 demo
|
|
|
|
|
|
```
|
|
|
postgres@hqdc034:~$ createdb demo
|
|
|
postgres@hqdc034:~$ psql demo < /home/changch/Downloads/demo.sql
|
|
|
SET
|
|
|
SET
|
|
|
略...
|
|
|
```
|
|
|
|
|
|
再檢查一次資料庫的狀況，看到 demo DB出現了，資料庫目錄也變大了
|
|
|
```
|
|
|
postgres@hqdc034:~$ psql -c '\l'
|
|
|
List of databases
|
|
|
Name | Owner | Encoding | Collate | Ctype | Access privileges
|
|
|
-----------+----------+----------+-------------+-------------+-----------------------
|
|
|
demo | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
|
|
|
postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
|
|
|
template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
|
|
|
| | | | | postgres=CTc/postgres
|
|
|
template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
|
|
|
| | | | | postgres=CTc/postgres
|
|
|
(4 rows)
|
|
|
|
|
|
postgres@hqdc034:~$ du -sh /zp/database/10/main/
|
|
|
2.1G /zp/database/10/main/
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
|
|
|
#### 建立第二次快照
|
|
|
這次的快照，將包含剛剛倒回的 demo DB，但是不包含等下才要建立的測試 table
|
|
|
```
|
|
|
2019-09-06 09:16:01 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 250K - 231M -
|
|
|
zp/database@demo_db_just_restore 0 - 2.08G -
|
|
|
2019-09-06 09:16:04 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
|
|
|
#### 建立測試 table
|
|
|
```
|
|
|
postgres@hqdc034:~$ psql -c 'create table test ( a int, b varchar(50) );'
|
|
|
CREATE TABLE
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
#### 建立第三次快照
|
|
|
這次快照，只有建立 test table ，但是裡面沒有資料
|
|
|
```
|
|
|
2019-09-06 09:18:34 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 250K - 231M -
|
|
|
zp/database@demo_db_just_restore 138K - 2.08G -
|
|
|
zp/database@demo_db_create_test_table_but_no_data 0 - 2.08G -
|
|
|
2019-09-06 09:18:36 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
#### 在test table 插入100萬筆資料
|
|
|
```
|
|
|
postgres@hqdc034:~$ psql -c 'with aa as ( select * from generate_series (1,1000000) a ) insert into test select aa.a, md5(aa.a::varchar) from aa;'
|
|
|
INSERT 0 1000000
|
|
|
postgres@hqdc034:~$ psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
---------
|
|
|
1000000
|
|
|
(1 row)
|
|
|
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
#### 建立第四次快照
|
|
|
test table 內有 1000000 筆資料
|
|
|
```
|
|
|
2019-09-06 09:18:36 [changch@hqdc034 ~]$ sudo zfs snapshot zp/database@demo_db_test_table_with_1M_rows
|
|
|
2019-09-06 09:21:08 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 250K - 231M -
|
|
|
zp/database@demo_db_just_restore 138K - 2.08G -
|
|
|
zp/database@demo_db_create_test_table_but_no_data 116K - 2.08G -
|
|
|
zp/database@demo_db_test_table_with_1M_rows 0 - 2.15G -
|
|
|
2019-09-06 09:21:09 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
|
|
|
#### 再次插入 100萬筆資料
|
|
|
```
|
|
|
postgres@hqdc034:~$ time psql -c 'with aa as ( select * from generate_series (1,1000000) a ) insert into test select aa.a, md5(aa.a::varchar) from aa;'
|
|
|
INSERT 0 1000000
|
|
|
|
|
|
real 0m4.276s
|
|
|
user 0m0.020s
|
|
|
sys 0m0.012s
|
|
|
postgres@hqdc034:~$ psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
---------
|
|
|
2000000
|
|
|
(1 row)
|
|
|
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
|
|
|
#### 建立第五次快照
|
|
|
現在 test table 有 200萬筆資料了
|
|
|
```
|
|
|
2019-09-06 09:21:09 [changch@hqdc034 ~]$ sudo zfs snapshot zp/database@demo_db_test_table_with_2M_rows
|
|
|
2019-09-06 09:22:29 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 250K - 231M -
|
|
|
zp/database@demo_db_just_restore 138K - 2.08G -
|
|
|
zp/database@demo_db_create_test_table_but_no_data 116K - 2.08G -
|
|
|
zp/database@demo_db_test_table_with_1M_rows 218K - 2.15G -
|
|
|
zp/database@demo_db_test_table_with_2M_rows 0 - 2.23G -
|
|
|
2019-09-06 09:22:30 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
#### 玩大點，直接湊滿1000萬筆資料好了
|
|
|
```
|
|
|
postgres@hqdc034:~$ time psql -c 'with aa as ( select * from generate_series (1,8000000) a ) insert into test select aa.a, md5(aa.a::varchar) from aa;'
|
|
|
INSERT 0 8000000
|
|
|
|
|
|
real 0m32.172s
|
|
|
user 0m0.024s
|
|
|
sys 0m0.008s
|
|
|
postgres@hqdc034:~$ psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
----------
|
|
|
10000000
|
|
|
(1 row)
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
|
|
|
#### 建立第六次快照
|
|
|
10M rows in test table
|
|
|
```
|
|
|
2019-09-06 09:22:30 [changch@hqdc034 ~]$ sudo zfs snapshot zp/database@demo_db_test_table_with_10M_rows
|
|
|
2019-09-06 09:25:18 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 250K - 231M -
|
|
|
zp/database@demo_db_just_restore 138K - 2.08G -
|
|
|
zp/database@demo_db_create_test_table_but_no_data 116K - 2.08G -
|
|
|
zp/database@demo_db_test_table_with_1M_rows 218K - 2.15G -
|
|
|
zp/database@demo_db_test_table_with_2M_rows 530K - 2.23G -
|
|
|
zp/database@demo_db_test_table_with_10M_rows 163K - 2.97G -
|
|
|
2019-09-06 09:25:21 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
|
|
|
到1000萬筆資料為止，現在資料庫大小是這樣
|
|
|
```
|
|
|
postgres@hqdc034:~$ du -sh /zp/database/10/main/
|
|
|
3.0G /zp/database/10/main/
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
|
|
|
|
|
|
***
|
|
|
### 還原測試
|
|
|
|
|
|
最後一次做快照的時候，demo DB 裡面有一千萬筆資料，現在來砍掉500萬筆
|
|
|
```
|
|
|
postgres@hqdc034:~$ time psql -c 'delete from test where a > 5000000;'
|
|
|
DELETE 3000000
|
|
|
|
|
|
real 0m7.844s
|
|
|
user 0m0.024s
|
|
|
sys 0m0.004s
|
|
|
|
|
|
postgres@hqdc034:~$ time psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
---------
|
|
|
7000000
|
|
|
(1 row)
|
|
|
|
|
|
|
|
|
real 0m0.268s
|
|
|
user 0m0.024s
|
|
|
sys 0m0.004s
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
咦，怪怪的，為什麼只有砍掉300萬筆？
|
|
|
好，這邊先不管，等等正好來驗證restore的狀況
|
|
|
|
|
|
假設剛剛這個刪除是錯誤的動作，我要回到1000萬資料的狀態，就可以用zfs rollback 來達成
|
|
|
|
|
|
#### 第一次還原
|
|
|
目標是還原到包含1000萬筆資料的狀態(現在是700萬筆)
|
|
|
|
|
|
```
|
|
|
2019-09-06 09:25:21 [changch@hqdc034 ~]$ sudo service postgresql stop
|
|
|
* Stopping PostgreSQL 10 database server [ OK ]
|
|
|
2019-09-06 10:14:12 [changch@hqdc034 ~]$ sudo zfs rollback -r zp/database@demo_db_test_table_with_10M_rows
|
|
|
2019-09-06 10:14:28 [changch@hqdc034 ~]$ sudo service postgresql start
|
|
|
* Starting PostgreSQL 10 database server [ OK ]
|
|
|
2019-09-06 10:14:57 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
檢查一下
|
|
|
```
|
|
|
postgres@hqdc034:~$ time psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
----------
|
|
|
10000000
|
|
|
(1 row)
|
|
|
|
|
|
|
|
|
real 0m5.019s
|
|
|
user 0m0.040s
|
|
|
sys 0m0.008s
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
沒錯，又回到1000萬筆資料的狀態了
|
|
|
|
|
|
要注意的是，如果回到更之前的狀態，在該狀態之後的快照將會被清除，除非你先做clone
|
|
|
比如我現在要回到 200萬筆的狀態，那1000萬筆資料的快照就會被刪除
|
|
|
```
|
|
|
2019-09-06 10:17:32 [changch@hqdc034 ~]$ sudo service postgresql stop
|
|
|
* Stopping PostgreSQL 10 database server [ OK ]
|
|
|
2019-09-06 10:18:50 [changch@hqdc034 ~]$ sudo zfs rollback -r zp/database@demo_db_test_table_with_2M_rows
|
|
|
2019-09-06 10:18:57 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 250K - 231M -
|
|
|
zp/database@demo_db_just_restore 138K - 2.08G -
|
|
|
zp/database@demo_db_create_test_table_but_no_data 116K - 2.08G -
|
|
|
zp/database@demo_db_test_table_with_1M_rows 218K - 2.15G -
|
|
|
zp/database@demo_db_test_table_with_2M_rows 0 - 2.23G -
|
|
|
2019-09-06 10:19:04 [changch@hqdc034 ~]$ sudo service postgresql start
|
|
|
* Starting PostgreSQL 10 database server [ OK ]
|
|
|
2019-09-06 10:19:17 [changch@hqdc034 ~]$
|
|
|
|
|
|
postgres@hqdc034:~$ time psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
---------
|
|
|
2000000
|
|
|
(1 row)
|
|
|
|
|
|
real 0m0.175s
|
|
|
user 0m0.024s
|
|
|
sys 0m0.008s
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
|
|
|
啊，我剛剛應該先clone的....
|
|
|
沒關係，我們再做一次，新增800萬筆資料，湊齊1000萬筆，然後快照
|
|
|
```
|
|
|
postgres@hqdc034:~$ time psql -c 'with aa as ( select * from generate_series (1,8000000) a ) insert into test select aa.a, md5(aa.a::varchar) from aa;'
|
|
|
INSERT 0 8000000
|
|
|
|
|
|
real 0m35.662s
|
|
|
user 0m0.048s
|
|
|
sys 0m0.004s
|
|
|
postgres@hqdc034:~$ time psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
----------
|
|
|
10000000
|
|
|
(1 row)
|
|
|
|
|
|
real 0m5.259s
|
|
|
user 0m0.024s
|
|
|
sys 0m0.008s
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
做快照
|
|
|
```
|
|
|
2019-09-06 10:19:17 [changch@hqdc034 ~]$ sudo zfs snapshot zp/database@demo_db_test_table_with_10M_rows
|
|
|
2019-09-06 10:22:59 [changch@hqdc034 ~]$ sudo zfs list -t snapshot
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp/database@init_db_no_demo 250K - 231M -
|
|
|
zp/database@demo_db_just_restore 138K - 2.08G -
|
|
|
zp/database@demo_db_create_test_table_but_no_data 116K - 2.08G -
|
|
|
zp/database@demo_db_test_table_with_1M_rows 218K - 2.15G -
|
|
|
zp/database@demo_db_test_table_with_2M_rows 56.4M - 2.23G -
|
|
|
zp/database@demo_db_test_table_with_10M_rows 0 - 1.81G -
|
|
|
2019-09-06 10:23:02 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
接著來測試看看 clone snapshot，這是基本的說明
|
|
|
```
|
|
|
Clones can only be created from a snapshot and a snapshot can not
|
|
|
be deleted until you delete the clone that is based on this snapshot.
|
|
|
To create a clone, use the zfs clone command.
|
|
|
```
|
|
|
clone 會做出一份跟clone來源一模一樣的資料，在快照模式下，資料是唯讀的，clone出來後，就可以做異動。但是不能刪除clone來源的快照，會提示錯誤。
|
|
|
```
|
|
|
2019-09-06 10:28:31 [changch@hqdc034 ~]$ sudo zfs clone zp/database@demo_db_test_table_with_10M_rows zp/database/clone_with_10M_rows
|
|
|
2019-09-06 10:29:21 [changch@hqdc034 ~]$ sudo zfs list
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp 3.08G 231G 22K /zp
|
|
|
zp/database 3.08G 231G 1.88G /zp/database
|
|
|
zp/database/clone_with_10M_rows 0 231G 1.81G /zp/database/clone_with_10M_rows
|
|
|
2019-09-06 10:29:26 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
可以看到做了clone之後，多了一個 zfs dataset
|
|
|
試試看把資料庫路徑直接改到這個新做的dataset 看看能不能啟動資料庫
|
|
|
修改 /etc/postgresql/10/main/postgresql.conf，然後重起postgresql
|
|
|
|
|
|
|
|
|
```
|
|
|
#data_directory = '/var/lib/postgresql/10/main' # use data in another directory
|
|
|
#data_directory = '/zp/database/10/main'
|
|
|
data_directory = '/zp/database/clone_with_10M_rows/10/main'
|
|
|
```
|
|
|
|
|
|
**啟動有比較久一點** 而且好像沒成功啟動
|
|
|
```
|
|
|
2019-09-06 10:32:27 [changch@hqdc034 ~]$ sudo service postgresql restart
|
|
|
* Restarting PostgreSQL 10 database server [ OK ]
|
|
|
2019-09-06 10:33:37 [changch@hqdc034 ~]$
|
|
|
2019-09-06 10:33:37 [changch@hqdc034 ~]$ sudo netstat -antlp |grep 5432
|
|
|
```
|
|
|
而且在 syslog & postgresql log 中看不到什麼異常，怪了！
|
|
|
而且再啟動一次就好了？
|
|
|
|
|
|
再來測試一次看看
|
|
|
```
|
|
|
2019-09-06 10:37:22 [changch@hqdc034 ~]$ sudo service postgresql stop
|
|
|
* Stopping PostgreSQL 10 database server [ OK ]
|
|
|
2019-09-06 10:38:03 [changch@hqdc034 ~]$ sudo zfs list
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp 3.24G 231G 22K /zp
|
|
|
zp/database 3.24G 231G 1.88G /zp/database
|
|
|
zp/database/clone_with_10M_rows 165M 231G 1.88G /zp/database/clone_with_10M_rows
|
|
|
2019-09-06 10:38:13 [changch@hqdc034 ~]$ sudo zfs destroy zp/database/clone_with_10M_rows
|
|
|
2019-09-06 10:38:21 [changch@hqdc034 ~]$ sudo zfs clone zp/database@demo_db_test_table_with_10M_rows zp/database/clone_with_10M_rows
|
|
|
2019-09-06 10:38:32 [changch@hqdc034 ~]$ sudo zfs list
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp 3.08G 231G 22K /zp
|
|
|
zp/database 3.08G 231G 1.88G /zp/database
|
|
|
zp/database/clone_with_10M_rows 0 231G 1.81G /zp/database/clone_with_10M_rows
|
|
|
2019-09-06 10:38:35 [changch@hqdc034 ~]$ sudo service postgresql start^C
|
|
|
2019-09-06 10:38:44 [changch@hqdc034 ~]$ sudo zfs list
|
|
|
NAME USED AVAIL REFER MOUNTPOINT
|
|
|
zp 3.08G 231G 22K /zp
|
|
|
zp/database 3.08G 231G 1.88G /zp/database
|
|
|
zp/database/clone_with_10M_rows 0 231G 1.81G /zp/database/clone_with_10M_rows
|
|
|
2019-09-06 10:38:45 [changch@hqdc034 ~]$ sudo service postgresql start
|
|
|
* Starting PostgreSQL 10 database server [ OK ]
|
|
|
2019-09-06 10:39:04 [changch@hqdc034 ~]$ netstat -antlp |grep 5432
|
|
|
(Not all processes could be identified, non-owned process info
|
|
|
will not be shown, you would have to be root to see it all.)
|
|
|
tcp 0 0 0.0.0.0:5432 0.0.0.0:* LISTEN -
|
|
|
tcp6 0 0 :::5432 :::* LISTEN -
|
|
|
2019-09-06 10:39:13 [changch@hqdc034 ~]$
|
|
|
```
|
|
|
這次就沒問題？看來是我第一次下指令的時候，不該用sudo netstat -antlp 去檢查？
|
|
|
anyway ，回到psql 來看看內容
|
|
|
```
|
|
|
postgres@hqdc034:~$ time psql -c 'select count(*) from test;'
|
|
|
count
|
|
|
----------
|
|
|
10000000
|
|
|
(1 row)
|
|
|
|
|
|
|
|
|
real 0m4.716s
|
|
|
user 0m0.028s
|
|
|
sys 0m0.004s
|
|
|
postgres@hqdc034:~$
|
|
|
```
|
|
|
|
|
|
Good ，clone 出來的果然是1000萬筆資料時的狀態
|
|
|
|
|
|
***
|
|
|
|
|
|
這次測試就先到此為止，後面再來測試zfs的 replication and send/recv
|
