Looking for advice on migration to new Cyrus-IMAPd server

[Patrick Boutilier]

On 03/12/2011 09:35 AM, Bron Gondwana wrote:
> On Sat, Mar 12, 2011 at 02:20:04PM +0100, Simon Matter wrote:
>>> I've built a new Cyrus-IMAPd server (hardware).   It has two sets
>>> of mirrored disks.  The OS is on WD VelociRaptor 450GB drives.  The
>>> bulk IMAP data will be on WD Black RE-4 2TB drives.  So far, I think
>>> I want to use ZFS for both mirrors.
>>>
>>> I wanted to see what the list recommends for the migration.
>>>
>>> The current server is running FreeBSD 8.2, with cyrus-imapd-2.3.16
>>> on a RAID-5 setup on SCSI-UW with 15000RPM drives.  We get about
>>> 1.5 - 9MB/s at 80 - 100% busy according to "systat -vm 1" for most
>>> of the day.
>>>
>>> The existing server has no metadata partition.  On the new server,
>>> I believe that I want to put the config directory and metadata
>>> partition on the 46050GB drives and the message files on the 2TB drives.
>>>
>>> Can I configure the new server's imapd.conf to put data where I
>>> want it, and simply use the cyrus replication to put the data in
>>> the right place on the new server?  In other words can the migration
>>> split my data partition into data and metadata partitions without
>>> my having to script up shuffling files around then reconfiguring
>>> and restarting cyrus?
>>
>> I can't comment on this one. I've tried metadata partitions but never
>> tried doing it online.
>
> Cyrus won't move them for you, and I don't think there is even a tool
> to do it.  Sorry.

I used tools/migrate-metadata from the source tarball (2.3.16) to 
migrate an existing setup (same server) to using a metadata partition.

As for setting up the slave with a metadata partition and then 
replicating from the old server to the new, I think that might work. 
Just set it up and replicate one user. That should indicate if it will 
work on not.



>
>>> Also, should I install Cyrus-IMAPd 2.3 or 2.4 on the new server?
>>> I tend to be a late adopter.  I'm wondering if 2.4 is generally
>>> considered ready for a single server install in a multi-domain ISP
>>> type environment.
>>
>> Personally I consider 2.4 as stable as 2.3. It has worked very well for us.
>
> I am biased here ;)  I think 2.4 is a lot better, but not as
> "battle tested".  There are some known bugs I'm hoping to fix
> with another 2.4 release very soon.
>
> Bron.
> ----
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