From: Michael Slusarz Date: Wed, 20 Apr 2016 01:24:52 +0000 (-0600) Subject: man: Add more complete description of one-way sync X-Git-Tag: 2.3.0.rc1~3929 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e43979fa09dc4a8eb774cb5476edd71544d39e44;p=thirdparty%2Fdovecot%2Fcore.git man: Add more complete description of one-way sync --- diff --git a/doc/man/doveadm-sync.1.in b/doc/man/doveadm-sync.1.in index 2d56391e63..7b69bbe599 100644 --- a/doc/man/doveadm-sync.1.in +++ b/doc/man/doveadm-sync.1.in @@ -74,6 +74,33 @@ multiple times, then switch mails to be delivered to the new mailbox and run .B doveadm sync \-1 once more to transfer any last new mails from the old mailbox. +.IP +The one\-way algorithm is the same as two-way dsync algorithm except the +source account is not modified. It fetches the message's GUID (Global UID), +which is used to identify any conflicting UIDs in messages. As long as the +source and destination side has matching UID<\->GUID mapping, those emails +are assumed to be synced correctly. Only after the first mismatch will +changes begin. +.IP +Example: Source mailbox has messages UID 1..5; source mailbox is sync'd +using +.B doveadm backup +to the destination. Subsequently, UID 6 is delivered to the source mailbox +and UID 1 is expunged from the destination mailbox. In this example, UID 1 +is kept removed (in destination) because UID 1..5 have identical +Date+Message\-ID headers. UID 6 is not seen in destination so it's copied. +.IP +If both source and destination have UID 6, but the messages are different, +the headers don't match and both the messages are kept in the destination but +they're given new UIDs 7 and 8 just to be sure any client didn't get confused +about what UID 11 actually was. Thus, one\-way sync begins to quickly diverge +from the source mailbox once changes start to occur on either side; one\-way +sync should therefore normally only be used within a short period of time +after a +.B doveadm backup +or +.B doveadm sync +command was used to synchronize the mailboxes. .\"------------------------------------- .RE .PP