Re: Проблема при бэкапе.

Привет, Николай!

2014-04-03 11:44 GMT+04:00 Николай Богданов <nikolay.bogdanov@flant.ru>:

День добрый. Использую Continuous Archiving для бэкапов и столкнулся с проблемой.

После SELECT pg_start_backup('pgbackup', true); начинаю копирование данных, в это же время postgres решает очистить несколько файлов. В результате имею неконсистентный бэкап.

Вы где-то ошиблись и что-то делаете не правильно, или копирование WAL или их применение при разворачивании. 

pg_start_backup и последующее применение всех WAL сгенерированных с начала pg_start_backup до pg_stop_backup

к копии при разворачивании бекапа гарантируют консистентность, независимо от того, какие файлы там создавались

или очищались в процессе копирования.

--
Sergey Burladyan

Сергей, я наверное неверно выразился. С WAL-файлами проблем нет. Проблемы с файлами страниц внутри кластера. Вот кусочек лога сегодняшнего бэкапа.

+ ssh postgres@172.26.1.15 /opt/scripts/start_backup.sh
 pg_start_backup
-----------------
 14E1/6D000020
(1 строка)

+ rsyncload -a -v --bwlimit=100000 --exclude=pg_xlog --exclude=pg_log --exclude=server.crt --exclude=server.key --exclude=/var/lib/postgresql/9.2/main/server.key rsync://10.0.0.2/root//var/lib/postgresql/9.2/main/ /var/tmp/db
---skip---
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204170" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204171" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204172" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204173" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204174" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204174_fsm" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204175" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204176" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204177" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204178" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204179" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204180" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204181" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204182" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204183" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204184" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204185" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204186" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204187" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204188" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204189" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204190" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204191" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204192" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204193" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204194" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204195" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204196" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204197" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204198" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204199" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204200" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204201" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204202" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204203" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204204" (in root)
file has vanished: "/var/lib/postgresql/9.2/main/base/16420/33204205" (in root)
---skip---
rsync warning: some files vanished before they could be transferred (code 24) at main.c(1536) [generator=3.0.9]
+ export e=24
+ e=24

То есть после  pg_start_backup у меня сам postgres очистил несколько файликов. После чего я сказал pg_stop_backup и начал восстанавление.
Восстановление базы прошло без проблем, но при определенных запросах база выдает, что не может найти файл.

Собственно я пытаюсь понять - где я документацию не дочитал.

-- 
Николай Богданов,
инженер ЗАО «Флант»
http://flant.ru/
+7 (495) 721-10-27, доб. 422
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