Question about "Disaster Recovery"

[piter]

Hi,

I never tried to simulate a disaster recovery yet, but reading this

Zx Backup: Disaster Recovery - ZeXtras Suite Wiki

I don't understand, why it is stated:

The Recovery Process
Install Zimbra on a new server and configure the Server and Global settings EXACTLY as they were on the old machine.

I was thinking I could recover the configuration of Server and Global settings too... isn't it? What am I missing?

Thanks in advance for make this clear!

[Cine]

Hello piter!

Server and Global settings are indeed backed up by ZeXtras Backup, and can be viewed through the `getServerConfig` ZeXtras Backup CLI command, but are not restored automatically due to the extremely sensitive nature of those settings where a slight change in the surrounding environment can lead to service disruption.

Furthermore this, together with ZeXtras Backup's flexibility, allows you to restore your data to a server with a different OS/Zimbra Release/Networking/Storage setup without any constraints other than the minimum Zimbra version required to run ZeXtras Suite.

Thank you very much for your feedback, I'll update the guide to make the whats and whys it clearer

Have a nice day,
Cine
the ZeXtras Team

[Cine]

Hello!

I've updated the guide with the information discussed above, I'm taking this opportunity to further expand the guide with some pointers about performing a disaster recovery in a virtual environment featuring snapshot-based backups!

Thank you again

Cine
the ZeXtras Team

[piter]

Thanks to you! Now it's very detailed!

Just a few more questions to be sure:

1) I understood there is no way to restore the configuration by command, but can you suggest a way to display at least a "diff" view between the server and the backed up configuration? I think this could be extremely helpful to save time in that situation. In that way you can see just the config modification you have to change.

2) about the previous VM restore:

Doing so will parse all items in the Backup Path and import the missing ones, speeding up the Disaster Recovery by a good measure

so Zextras will just make a perfect "diff" between the last VM state and the last Zextras backup?

more specifically:

a) after recovery I will not find duplicates, if already present in the VM?
b) if I have an element in the VM, that later has been deleted and not present in the Zextras backup, will this be correctly purged from the VM ?

Thanks again for everything!

[Cine]

Hello piter!

Glad you like the improved guide

1) I understood there is no way to restore the configuration by command, but can you suggest a way to display at least a "diff" view between the server and the backed up configuration? I think this could be extremely helpful to save time in that situation. In that way you can see just the config modification you have to change.

Alas, I won't...
Something like a side-by-side diff of the old and new server's configuration is risky, as settings and requirements often change based on the Zimbra version (e.g. the MaxPermSize part of the mailboxd_java_options config value from Z7 to Z8), and even when running the same Zimbra versions there are some settings you wouldn't want to carry over such as deprecated config keys - which are not deleted from the config when Zimbra is updated - or customizations.

I will, however, provide you with a simple oneliner that will display the `getServerConfig` output in a more localconfig-like manner:

zxsuite backup getServerConfig standard file /old/backup/path/server/backup_18_12_14#14_46_13 query localConfig | sed -r 's/__+/: /' | sort | less

Hope this helps at least a bit!

2) about the previous VM restore:

Doing so will parse all items in the Backup Path and import the missing ones, speeding up the Disaster Recovery by a good measure

so Zextras will just make a perfect "diff" between the last VM state and the last Zextras backup?

Yes: ZeXtras Backup's External Restore will skip all existing items import any item in the backup path that's not in Zimbra. The check is done on each item's "item ID", so in order for this to work it's vital to inhibit user access and email traffic when prompted in the guide.

a) after recovery I will not find duplicates, if already present in the VM?

Exactly!

b) if I have an element in the VM, that later has been deleted and not present in the Zextras backup, will this be correctly purged from the VM ?

No, ZeXtras Backup's restore mode don't move/delete any item, so users will need to manually delete those items again.
ZeXtras Suite 2.2 will feature a huge set of changes and improvements in ZxBackup, so this is going to change in late 2015.

Thanks again for everything!

You're welcome!

Have a nice day,
Cine
the ZeXtras Team