[Users] ZCS OSE Hot DR Solutions

[Andrew Martin]

----- Original Message -----
> From: "Andreas Wolske" <andreas.wolske at managedhosting.de>
> To: "amartin" <amartin at xes-inc.com>
> Cc: "gebhardt" <gebhardt at openfactory.ch>, "users" <users at lists.zetalliance.org>
> Sent: Wednesday, September 28, 2016 1:30:45 AM
> Subject: Re: [Users] ZCS OSE Hot DR Solutions

> Good Morning,
> 
> Am 27.09.2016 um 21:05 schrieb Andrew Martin:
>> ----- Original Message -----
>>> From: "Andreas Wolske" <andreas.wolske at managedhosting.de>
>>> To: "amartin" <amartin at xes-inc.com>
>>> Cc: "gebhardt" <gebhardt at openfactory.ch>, "users" <users at lists.zetalliance.org>
>>> Sent: Tuesday, September 27, 2016 1:03:06 PM
>>> Subject: Re: [Users] ZCS OSE Hot DR Solutions
>> 
>>> Hi Andrew,
>>>
>>> ----- Am 27. Sep 2016 um 18:19 schrieb Andrew Martin amartin at xes-inc.com:
>>>
>>>> Andreas,
>>>>
>>>> Thanks, I had considered using XtraBackup as well, however you still have
>>>> the problem of the time period between when XtraBackup runs and when
>>>> /opt/zimbra/store
>>>> is saved off. Unless these are coordinated, you could end up with some message
>>>> metadata in the db which doesn't have a corresponding file in /opt/zimbra/store
>>>> or vise versa. How do you ensure that the backup is fully self-consistent?
>>>
>>> Before running the XtraBackup we do a "ZimbraAccountStatus Maintenance" for all
>>> accounts
>>> in sync with LVM Snapshot of /opt/zimbra/store and LDAP Dump.
>>> This makes sure that incoming mails are being queued within the MTA and no
>>> MetaData changes occur.
>>> Also the login is being disabled so that users can not add adresses or Mobile
>>> Devices etc.
>>> during the backup time window. The XtraBackup does only take a couple of
>>> minutes for approx. 25G of MySQL. So thats a viable solution for me
>>> provided that the Backup will run 3 am for about 15 Minutes.
>>>
>> Andreas,
>> 
>> Nice, this sounds like a good solution! Does setting "ZimbraAccountStatus
>> Maintenance"
>> prevent the messages from being saved to /opt/zimbra/store as well?
> 
> Yep. Incoming E-Mails are being queued in the MTA as long as the
> account status is "Maintenance".
> 
>> If you're already locking the user accounts, I suppose you could get away
>> without
>> using XtraBackup by locking all tables:
>> FLUSH TABLES WITH READ LOCK
>> mysqldump
>> UNLOCK TABLES
> 
> I'm not a fan of locking all tables of a database at once
> and waiting for sequential sql dumps to be finished. The bigger the
> database grows the longer the dump takes because mysqldump doesn't
> support incremental backups and you have to do a full dump every day.
> 
> XtraBackups works closely with  InnoDB and its capabilities for
> incremental backups. So subsequent incremental backups take only a
> couple of seconds. Depending on how many IOPS the backup datastore
> can provide XtraBackup is much faster than mysqldump.
> 
> Current MariaDB versions use by Zimbra use InnoDB with
> "innodb_file_per_table" by default. So why not take advantage from
> the speed and features provided by InnoDB and XtraBackup?

Makes sense to me, thanks for the clarification.

Andrew