How to backup cyrus-imapd without stopping service

[Seiichirou Hiraoka]

Thanks everybody,

to Daniel Eckl>
  Thank you for consideration.
  I know the FQS to use Cyrus-IMAPD on NFS. But...
  historical details, I need to use and it looks work
  without problem...^_^;

Then...

From: Wesley Craig <wes at umich.edu>
Subject: Re: How to backup cyrus-imapd without stopping service
Date: Fri, 23 Jun 2006 10:31:03 -0400
Message-ID: <400EB816-06AB-437F-9702-ABD874DBC4FC at umich.edu>

> On 22 Jun 2006, at 23:53, Daniel O'Connor wrote:
> > On Friday 23 June 2006 12:17, Seiichirou Hiraoka wrote:
> >> So I want to know the better (or recommend) way to backup
> >> Cyrus-IMAPD /var/imap files to other host without stop
> >> service.
> >
> > AFAIK the only way to do it properly is to use snapshots on the  
> > file system,
> > and then use rsync or tar or whatever. If you use rsync the  
> > database will be
> > inconsistent with itself or other files.
> 
> If you're concerned that the databases files be consistent, then the  
> only way is to cleanly shutdown the processes that have the databases  
> open.  Snapshots will definitely NOT guarantee consistency of the  
> databases, since consistent database updates can take multiple  
> writes.  Take for example the recent discussion of database  
> corruption during sudden power lose.  Snapshots stop user process  
> file access very suddenly, not cleanly.  Problems created by  
> snapshots can usually be corrected with reconstruct.

How about to use rsync and reconstruct (on backup) without using
snapshot?

> The real question is, what are your backups for?  If you're concerned  
> about recovering mail that the user has deleted, then rsync-ing the  
> live system is fine.  If you want a consistent copy that you could  
> switch to in the event of a large-scale disaster, then you probably  
> want to explore application-level replication.

I want to switch main to backup host when main host is in trouble
(i.e. Fatal Hardware Error). So I want to backup Cyrus-IMAPD DBs
(/var/imap) and keep it consistent.

Best regards,

- flathill