How to backup cyrus-imapd without stopping service

[Wesley Craig]

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.

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.

:wes