[bareos-users] Percona xtrabackup plugin: pitfalls and hints

[Maik Aussendorf]

Hi,

some of you have reported problems and / or solutions regarding our
Percona / xtrabackup plugin.

I want to summarize some pitfalls and hints here.


1. Always incremental only works with file backups

A user reported problems like this
https://github.com/bareos/bareos-contrib/issues/33 on github

Please do not use Always Incremental with plugins as this won't work by
design. Compare documentation:
http://doc.bareos.org/master/html/bareos-manual-main-reference.html#AlwaysIncrementalConcept


2. Restore via webui does not work with (some) plugins

some people here have reported problems on restore like

2018-09-19 17:55:05 | bareos-fd JobId 1896: Error: python-fd: No lsn
information found in restore object for file
/tmp/bareos-restores//_percona/xbstream.0000000355 from job 355

As of now, the web UI does not ensure to restore extra information
called "restore object". Plugins that rely on these kind of
extra-information will fail on restore. This problem was also reported
for the VMWare plugin and a bug-report exists:

https://bugs.bareos.org/view.php?id=805

Thanks to Geoffrey McRae for reporting this and sending a patch / pull
request. We will evaluate this pull request and include it, unless we
find any side-effects. Please follow the pull-request to get updates on
this issue:

https://github.com/bareos/bareos/pull/119

Workaround: use bconsole to select files for restore, when plugins are
involved in the restore process.



3. Restore problems with filesets containing File = .. AND Plugin = ..
directives

When using filesets with plugins and files mixed, like

 File = /etc
 Plugin =
"python:module_path=/usr/lib64/bareos/plugins:module_name=bareos-fd-percona"

You might get errors on restore. If you choose to restore both - plugin
data and files - and files are included in incremental backups, you may
hit error messages like

2018-10-09 15:25:15 10.20.240.244-fd JobId 43240: Error:
filed/fd_plugins.cc:1247 Unbalanced call to createFile=0 0

We will work on a fix. Please observe bug-report
https://bugs.bareos.org/view.php?id=1021

Workaround:
- use dedicated filesets when using plugins
- try to restore plugin and files separately (not verified that this
works under all circumstances).

Regards
Maik
--
With kind regards // Mit freundlichen Grüßen
--
Maik Außendorf ***@bareos.com
Bareos GmbH & Co. KG Phone: [phone]
http://www.bareos.com

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