dovecot - Aug 2020 - Backup questions - errors

Hi,

although i've search the archives, there are questions left regarding
backup strategies and errors that occur.

I'm using dovecot 2.3.11.3 with mdbox (mailbox size 50MB - 30GB).

Every night, i ran the following command:

doveadm -o mail_fsync=never -o plugin/quota= -o plugin/zlib_save=gz \
	backup -u account mdbox:/nfs/storage/account/mdbox


### incremental backup
Thanks to zlib compression, i save a lot of storage space, nonetheless
i'd go with an incremental backup, but it seems to only merge changes,
comparing to rsyncs' --link-dest option where you can put all "changes
of the day" in an extra folder. I'd like to prevent loosing mail that
gets deleted by accident/on purpose. How can i achieve this with dsync
and w/o doing a full backup every day?



### backup errors
After a few days w/o any errors, doveadm prints the following lines (only
for the biggest, 30GB mailbox) two days in a row. As dovecot has self-
healing capabilities, i think these errors/warnings can be ignored and
should go away...?

Error: Transaction log ....mdbox/dovecot.list.index.log: duplicate transaction
log sequence (38)
Error: Index ....mdbox/dovecot.list.index: Lost log for seq=38 offset=63312:
Missing middle file
seq=38 (between 38..4294967295, we have seqs 37,39): .log.2 contains file_seq=37
(initial_mapped=1,
reason=Index mapped)
Warning: fscking index file ....mdbox/dovecot.list.index
Error: Fixed index file ....mdbox/dovecot.list.index: log_file_seq 38 -> 39
Error: Mailbox list index was marked as fsck'd ....mdbox/dovecot.list.index
Error: Mailbox list index was marked as fsck'd ....mdbox/dovecot.list.index
Error: Mailbox list index was marked as fsck'd ....mdbox/dovecot.list.index

Thanks,

	-Mark


-- 
Mark Patruck ( mark at wrapped.cx )
GPG key 0xF2865E51 / 187F F6D3 EE04 1DCE 1C74  F644 0D3C F66F F286 5E51

https://www.wrapped.cx

On 8/28/20 9:54 AM, Mark Patruck wrote:
> Hi,
> 
> although i've search the archives, there are questions left regarding
> backup strategies and errors that occur.
> 
> I'm using dovecot 2.3.11.3 with mdbox (mailbox size 50MB - 30GB).
> 
> Every night, i ran the following command:
> 
> doveadm -o mail_fsync=never -o plugin/quota= -o plugin/zlib_save=gz \
>  ????backup -u account mdbox:/nfs/storage/account/mdbox
> 
> 
> ### incremental backup
> Thanks to zlib compression, i save a lot of storage space, nonetheless
> i'd go with an incremental backup, but it seems to only merge changes,
> comparing to rsyncs' --link-dest option where you can put all
"changes
> of the day" in an extra folder. I'd like to prevent loosing mail
that
> gets deleted by accident/on purpose. How can i achieve this with dsync
> and w/o doing a full backup every day?
	Any info/recommendation on this? I still haven't found
	a solution yet.
> ### backup errors
> After a few days w/o any errors, doveadm prints the following lines (only
> for the biggest, 30GB mailbox) two days in a row. As dovecot has self-
> healing capabilities, i think these errors/warnings can be ignored and
> should go away...?
> 
> Error: Transaction log ....mdbox/dovecot.list.index.log: duplicate
transaction log sequence (38)
> Error: Index ....mdbox/dovecot.list.index: Lost log for seq=38
offset=63312: Missing middle file
> seq=38 (between 38..4294967295, we have seqs 37,39): .log.2 contains
file_seq=37 (initial_mapped=1,
> reason=Index mapped)
> Warning: fscking index file ....mdbox/dovecot.list.index
> Error: Fixed index file ....mdbox/dovecot.list.index: log_file_seq 38 ->
39
> Error: Mailbox list index was marked as fsck'd
....mdbox/dovecot.list.index
> Error: Mailbox list index was marked as fsck'd
....mdbox/dovecot.list.index
> Error: Mailbox list index was marked as fsck'd
....mdbox/dovecot.list.index
	As i already thought, these are gone. No new errors over the
	last days.
> Thanks,
> 
>  ????-Mark
> 
> 
-- 
Mark Patruck ( mark at wrapped.cx )
GPG key 0xF2865E51 / 187F F6D3 EE04 1DCE 1C74  F644 0D3C F66F F286 5E51

https://www.wrapped.cx