'batch move' of a few thousand mailboxes to different partitions

[Andrew Morgan]

On Wed, 18 Apr 2007, Eric Luyten wrote:

> Cyrus 2.2.13 on a Solaris 9 server
> 4 Cyrus spool partitions, 350 GB each, nearing 80% occupation
> (Hashing performed on first letter basis of account name)
>
> I have two extra 350 GB partitions ready and 'partition' lines
> already added to /etc/imapd.conf
>
>
> To spread out the mail data over six partitions I would need
> to move about 350 GB of mail.
>
> Two scenarios :
>
>  a) use rename_mailbox in cyradm
>
>       pro  : mail server can keep on running
>       cons : filesystem metadata changes
>              no 'batching' method available  (suggestions, anyone ?)
>              slow
>
>  b) use 'cp -p -r', update a text dump of mailboxes.db and regenerate
>
>       pros : filesystem metadata does not change
>              easily batchable
>              significantly faster than method a)
>       con  : mail server must be halted for (at least) several hours
>
>
> Am I overlooking important issues here ?

I would use method "a".  You can easily do the moves in batch using a perl 
script.  Here is a simple perl function we use to move users between 
murder backends:

----------------------------------------------------------------
##########################
# Move a mailbox between backends
##########################
sub move_backend {
         my ($server, $authuser, $authpw, $mailbox, $newbe) = @_;

         use Mail::IMAPClient;

         # Connect to Cyrus
         my $imap = Mail::IMAPClient->new(
                         Server => $server,
                         User => $authuser,
                         Password => $authpw
                         );

         if (! $imap) {
                 return "Cannot connect to mail server '$server' - $!";
         }

         # Make sure the mailbox exists
         if (! $imap->list($mailbox)) {
                 return "Error: Mailbox '$mailbox' not found.";
         }

         my @results = $imap->tag_and_run(qq/RENAME $mailbox $mailbox $newbe/);

         $imap->logout;

         foreach my $r (@results) {
                 $r =~ s/\r//g;
                 $r =~ s/\n//g;
                 if ($r =~ / NO (.*)/) {
                         return "Error: Rename of mailbox '$mailbox' failed 
- $1";
                 }
         }

         return "Success";
}
----------------------------------------------------------------

In a non-Murder environment, the third argument ($newbe) would be the 
partition instead.


Also, what does "cons : filesystem metadata changes" mean?

 	Andy