2.3.10 Upgrade Question

[Bron Gondwana]

On Tue, 20 Nov 2007 11:54:24 +0000, "Ian G Batten" <ian.batten at uk.fujitsu.com> said:
> 
> On 20 Nov 07, at 1146, Bron Gondwana wrote:
> 
> >
> > The index files are pretty small, and they rebuild fast :)  They  
> > get streamed
> > into new copies every single expunge anyway.
> 
> What's involved in the rebuild?  I have users with tens of thousands  
> of messages in a single mailbox, so delaying that open while it reads  
> and indexes a few gigs is bad.  Does the rebuild need to open every  
> message?  Read headers?  Bodies?  What?

No - thankfully everything you need is in the index record itself.
If you want the new sha1 GUIDs you need to reconstruct with the -G
flag, but that's not required for the upgrade.  The upgrade just pads
the GUID field with zeros.

It's really quick, we had folders with 200k messages in them, and the
upgrade was only a couple of seconds on a pretty busy server.  It's still
only 96 bytes per record or something, so that's pretty much streaming what,
18Mb or something - hardly giant given that it's all sequential reads and
writes, and the CPU isn't doing much work.

Bron.
-- 
  Bron Gondwana
  brong at fastmail.fm