Backing up m(d)box - rsync?
Hello,
I manage a small number of email accounts for a voluntary organisation on a shared hosting platform.
$ dovecot --version 2.3.13 (89f716dc2)
I would like to keep automated local backups, but do not have access to doveadm.
I have seen a couple of forum posts where users have have suggested that using rsync to backup m(d)box folders can corrupt dovecot's indexes, but there is no further explanation, and this is apparently not a problem for maildir. Our host seems to use mdbox.
Does doveadm provide some sort of transaction/locking mechanism to prevent consistency problems?
Others seem to recommend using tar but I don't see what difference that should make.
Given that cpanel backups (provided as tar.gz archives of the home directory) include mail/ and seem to be copies of the filesystem at a particular time (though not true "snapshots" as such), aren't these just as "safe" as an rsync-ed backup?
Can anyone confirm/deny/shed any light on the issue(s), if indeed any?
Many thanks, Gareth
i use https://github.com/tachtler/dovecot-backupregards sven -------- Ursprüngliche Nachricht --------Von: donotspam@fastmail.fm Datum: 16.08.23 15:29 (GMT+01:00) An: dovecot@dovecot.org Betreff: Backing up m(d)box - rsync? Hello,I manage a small number of email accounts for a voluntary organisation on a shared hosting platform.$ dovecot --version2.3.13 (89f716dc2)I would like to keep automated local backups, but do not have access to doveadm.I have seen a couple of forum posts where users have have suggested that using rsync to backup m(d)box folders can corrupt dovecot's indexes, but there is no further explanation, and this is apparently not a problem for maildir. Our host seems to use mdbox.Does doveadm provide some sort of transaction/locking mechanism to prevent consistency problems? Others seem to recommend using tar but I don't see what difference that should make.Given that cpanel backups (provided as tar.gz archives of the home directory) include mail/ and seem to be copies of the filesystem at a particular time (though not true "snapshots" as such), aren't these just as "safe" as an rsync-ed backup?Can anyone confirm/deny/shed any light on the issue(s), if indeed any?Many thanks,Gareth_______________________________________________dovecot mailing list -- dovecot@dovecot.orgTo unsubscribe send an email to dovecot-leave@dovecot.org
Thanks Sven but I get a 404 from that link. Gareth
On 16 Aug 2023, at 15:21, sven_roellig via dovecot dovecot@dovecot.org wrote:
i use https://github.com/tachtler/dovecot-backupregards sven -------- Ursprüngliche Nachricht --------Von: donotspam@fastmail.fm Datum: 16.08.23 15:29 (GMT+01:00) An: dovecot@dovecot.org Betreff: Backing up m(d)box - rsync? Hello,I manage a small number of email accounts for a voluntary organisation on a shared hosting platform.$ dovecot --version2.3.13 (89f716dc2)I would like to keep automated local backups, but do not have access to doveadm.I have seen a couple of forum posts where users have have suggested that using rsync to backup m(d)box folders can corrupt dovecot's indexes, but there is no further explanation, and this is apparently not a problem for maildir. Our host seems to use mdbox.Does doveadm provide some sort of transaction/locking mechanism to prevent consistency problems? Others seem to recommend using tar but I don't see what difference that should make.Given that cpanel backups (provided as tar.gz archives of the home directory) include mail/ and seem to be copies of the filesystem at a particular time (though not true "snapshots" as such), aren't these just as "safe" as an rsync-ed backup?Can anyone confirm/deny/shed any light on the issue(s), if indeed any?Many thanks,Gareth_______________________________________________dovecot mailing list -- dovecot@dovecot.orgTo unsubscribe send an email to dovecot-leave@dovecot.org
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https://github.com/tachtler/dovecot-backup
On 16.08.23 16:45, Gareth Evans wrote:
Thanks Sven but I get a 404 from that link. Gareth
On 16 Aug 2023, at 15:21, sven_roellig via dovecot dovecot@dovecot.org wrote:
i use https://github.com/tachtler/dovecot-backupregards sven -------- Ursprüngliche Nachricht --------Von: donotspam@fastmail.fm Datum: 16.08.23 15:29 (GMT+01:00) An: dovecot@dovecot.org Betreff: Backing up m(d)box - rsync? Hello,I manage a small number of email accounts for a voluntary organisation on a shared hosting platform.$ dovecot --version2.3.13 (89f716dc2)I would like to keep automated local backups, but do not have access to doveadm.I have seen a couple of forum posts where users have have suggested that using rsync to backup m(d)box folders can corrupt dovecot's indexes, but there is no further explanation, and this is apparently not a problem for maildir. Our host seems to use mdbox.Does doveadm provide some sort of transaction/locking mechanism to prevent consistency problems? Others seem to recommend using tar but I don't see what difference that should make.Given that cpanel backups (provided as tar.gz archives of the home directory) include mail/ and seem to be copies of the filesystem at a particular time (though not true "snapshots" as such), aren't these just as "safe" as an rsync-ed backup?Can anyone confirm/deny/shed any light on the issue(s), if indeed any?Many thanks,Gareth_______________________________________________dovecot mailing list -- dovecot@dovecot.orgTo unsubscribe send an email to dovecot-leave@dovecot.org
dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-leave@dovecot.org
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Actually it's fine, I had copied/pasted your "regards" too by mistake
Thanks G
On 16 Aug 2023, at 15:59, Gareth Evans donotspam@fastmail.fm wrote:
Thanks Sven but I get a 404 from that link. Gareth
On 16 Aug 2023, at 15:21, sven_roellig via dovecot dovecot@dovecot.org wrote:
i use https://github.com/tachtler/dovecot-backupregards sven -------- Ursprüngliche Nachricht --------Von: donotspam@fastmail.fm Datum: 16.08.23 15:29 (GMT+01:00) An: dovecot@dovecot.org Betreff: Backing up m(d)box - rsync? Hello,I manage a small number of email accounts for a voluntary organisation on a shared hosting platform.$ dovecot --version2.3.13 (89f716dc2)I would like to keep automated local backups, but do not have access to doveadm.I have seen a couple of forum posts where users have have suggested that using rsync to backup m(d)box folders can corrupt dovecot's indexes, but there is no further explanation, and this is apparently not a problem for maildir. Our host seems to use mdbox.Does doveadm provide some sort of transaction/locking mechanism to prevent consistency problems? Others seem to recommend using tar but I don't see what difference that should make.Given that cpanel backups (provided as tar.gz archives of the home directory) include mail/ and seem to be copies of the filesystem at a particular time (though not true "snapshots" as such), aren't these just as "safe" as an rsync-ed backup?Can anyone confirm/deny/shed any light on the issue(s), if indeed any?Many thanks,Gareth_______________________________________________dovecot mailing list -- dovecot@dovecot.orgTo unsubscribe send an email to dovecot-leave@dovecot.org
dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-leave@dovecot.org
... however it relies on doveadm which I don't have access to on a shared host.
I am looking into IMAP-based "doveadm backup" (ie running doveadm elsewhere) but I fear this will require an admin username/password which wouldn't be accessible on a shared host.
I would be grateful if anyone can offer insight re the rsync query.
Thanks Gareth
On 16 Aug 2023, at 16:04, Gareth Evans donotspam@fastmail.fm wrote:
Actually it's fine, I had copied/pasted your "regards" too by mistake
Thanks G
On 16 Aug 2023, at 15:59, Gareth Evans donotspam@fastmail.fm wrote:
Thanks Sven but I get a 404 from that link. Gareth
On 16 Aug 2023, at 15:21, sven_roellig via dovecot dovecot@dovecot.org wrote:
i use https://github.com/tachtler/dovecot-backupregards sven -------- Ursprüngliche Nachricht --------Von: donotspam@fastmail.fm Datum: 16.08.23 15:29 (GMT+01:00) An: dovecot@dovecot.org Betreff: Backing up m(d)box - rsync? Hello,I manage a small number of email accounts for a voluntary organisation on a shared hosting platform.$ dovecot --version2.3.13 (89f716dc2)I would like to keep automated local backups, but do not have access to doveadm.I have seen a couple of forum posts where users have have suggested that using rsync to backup m(d)box folders can corrupt dovecot's indexes, but there is no further explanation, and this is apparently not a problem for maildir. Our host seems to use mdbox.Does doveadm provide some sort of transaction/locking mechanism to prevent consistency problems? Others seem to recommend using tar but I don't see what difference that should make.Given that cpanel backups (provided as tar.gz archives of the home directory) include mail/ and seem to be copies of the filesystem at a particular time (though not true "snapshots" as such), aren't these just as "safe" as an rsync-ed backup?Can anyone confirm/deny/shed any light on the issue(s), if indeed any?Many thanks,Gareth_______________________________________________dovecot mailing list -- dovecot@dovecot.orgTo unsubscribe send an email to dovecot-leave@dovecot.org
dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-leave@dovecot.org
On 2023-08-16, Gareth Evans donotspam@fastmail.fm wrote:
... however it relies on doveadm which I don't have access to on a shared host.
I am looking into IMAP-based "doveadm backup" (ie running doveadm elsewhere) but I fear this will require an admin username/password which wouldn't be accessible on a shared host.
If you don't have admin access to add a master password configuration, but do have the account passwords for the various you want to backup, separate backup runs with either dovecot tools using imapc, or any standard imap sync programs, are probably simplest.
I would be grateful if anyone can offer insight re the rsync query.
I guess you'd probably need at least mmap_disable=yes on the server, but I don't know enough about it to know whether that will be enough by itself.
On 19 Aug 2023, at 00:31, Stuart Henderson stu.lists@spacehopper.org wrote:
On 2023-08-16, Gareth Evans donotspam@fastmail.fm wrote:
... however it relies on doveadm which I don't have access to on a shared host.
I am looking into IMAP-based "doveadm backup" (ie running doveadm elsewhere) but I fear this will require an admin username/password which wouldn't be accessible on a shared host.
If you don't have admin access to add a master password configuration, but do have the account passwords for the various you want to backup, separate backup runs with either dovecot tools using imapc, or any standard imap sync programs, are probably simplest.
I would be grateful if anyone can offer insight re the rsync query.
I guess you'd probably need at least mmap_disable=yes on the server, but I don't know enough about it to know whether that will be enough by itself.
OK thanks very much Gareth
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participants (5)
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donotspam＠fastmail.fm
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Gareth Evans
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infoomatic
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Stuart Henderson
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sven_roellig