On 05/04/2024 13:26 EEST Marc <marc@f1-outsourcing.eu> wrote:
breaking the mail index
Tangentially query: is Dveocot smart enough to optimize mailbox renaming to do index renaming (i.e. does not try to copy or recreate
indices)?
Dovecot is, if you use LAYOUT=index. This will use only mailbox GUID on disk, and the folder name is only in indexes (both list index and mailbox index for recovery purposes).
I would recommend using 2.3.21 with LAYOUT=index to avoid problems.
So you can just add this to an existing configuration, without the need to do anything? Like eg reindex or so? I always had the impression this affects how messages are stored.
mail_location = mdbox:xxxxxx:INDEX=xxxxxx:CONTROL=/xxxxxxx becomes: mail_location = mdbox:xxxxxx:INDEX=xxxxxx:CONTROL=/xxxxxxx:LAYOUT:index
Does this really speed things up?
You can't put it on existing setup just like that, you need to do storage format migration, or copy all the folders into their GUID folders when you do this.
It will speed things up and will also allow you to use almost anything as mailbox name.
I was in the process of setting up new server, it already had a few test mailboxes on it.
why do you mention this specific version 2.3.21? el9 still is at 2.3.16.
Because we have fixed issues with index layout since 2.3.16. It will work with 2.3.16 too but there are issues you'd probably not want to deal with, most importantly:
- LAYOUT=index List index rebuild was missing.
- LAYOUT=index: Duplicate GUIDs were not detected.which were added in 2.3.17 and futher fixed in later versions. It's a chore to dig up specific versions, so I recommend using the latest.
So if I add the LAYOUT:index to mail_location for my mdbox setup, it only renames Drafts,INBOX,Junk etc to some uuid (I guess)?
├── mdbox │ ├── dbox-alt-root │ ├── mailboxes │ │ ├── Drafts │ │ │ └── dbox-Mails │ │ ├── INBOX │ │ │ ├── dbox-Mails │ │ │ └── test │ │ │ └── dbox-Mails │ │ ├── Junk │ │ │ └── dbox-Mails │ │ ├── NotSpam │ │ │ └── dbox-Mails │ │ ├── Sent │ │ │ └── dbox-Mails │ │ └── Trash │ │ └── dbox-Mails │ └── storage │ ├── m.1 │ ├── m.2 │ ├── m.3 │ ├── m.4 │ ├── m.5 │ └── m.6
This server is offline any way. What would be the easiest way to do this migration? Something I can do directly on this server?
If there are only few accounts, you can configure new mail location with LAYOUT=index and use doveadm sync / backup to migrate mails there, then move things over the old stuff - or copy old stuff elsewhere and do the same to current location as new.
Aki