Questions about hardlinks, alternate storage and compression
Hi all, I have some questions about hardlinks, alternate storage and compression. I already scanned the list for related information and I have an idea of how things works, but I would like to have a definite answer.
System spec:
- CentOS 6.6 x64
- dovecot-2.0.9-8.el6_6.4.x86_64 RPM package/version
- sdbox mail store
About hardlinks: when sending the same message to two different recipients, I see that the two u.x files are created as two different files. Diffing them, I see that the only difference is a single char (see [1] for an example). My questions are: a) it is possible to tell dovecot to create a single file + a single hardlink (linkref=2)? As other IMAP servers support that features (eg: Cyrus, CommunigatePro, etc) I am wondering if I missed something in configuring dovecot... b) If it is not possible, can I run a script that compare the various files and substitute equal ones (minus the changing line) with hardlinks, or it will confuse dovecot? As a side note, why the changing line ever exists?
About alternate storage and compression: actually, I use a single mail_location without compression. I would like to have an alternate storage and to enable compression on it only, leaving the main location without compression. I if understand it correctly, it _should_ be done using a command similar to "doveadm -Dv -o "plugin/zlib_save=gz" altmove -uu testuser sentbefore 8d". I'm right thinking that it should work? I will really end with a primary uncompressed mail store and an alternate, zlib-compressed one?
Thank you all and sorry if I did some naive questions.
[1] 63c63 < G2fd0811c64be8e553d970000eaa8309f
G2ed0811c64be8e553d970000eaa8309f
-- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8
Hi all, any ideas?
Especially point n.1 (no hardlink when sending the same email to multiple addresses) confuse me a bit. Searching in old messages I even stumbled on some users stating that, using Dovecot LMTP server, they achieved what I want (one messagge, multiple hardlinks), but I am _already_ using LMTP with no avail...
Regards.
On 27/06/15 18:18, Gionatan Danti wrote:
Hi all, I have some questions about hardlinks, alternate storage and compression. I already scanned the list for related information and I have an idea of how things works, but I would like to have a definite answer.
System spec:
- CentOS 6.6 x64
- dovecot-2.0.9-8.el6_6.4.x86_64 RPM package/version
- sdbox mail store
About hardlinks: when sending the same message to two different recipients, I see that the two u.x files are created as two different files. Diffing them, I see that the only difference is a single char (see [1] for an example). My questions are: a) it is possible to tell dovecot to create a single file + a single hardlink (linkref=2)? As other IMAP servers support that features (eg: Cyrus, CommunigatePro, etc) I am wondering if I missed something in configuring dovecot... b) If it is not possible, can I run a script that compare the various files and substitute equal ones (minus the changing line) with hardlinks, or it will confuse dovecot? As a side note, why the changing line ever exists?
About alternate storage and compression: actually, I use a single mail_location without compression. I would like to have an alternate storage and to enable compression on it only, leaving the main location without compression. I if understand it correctly, it _should_ be done using a command similar to "doveadm -Dv -o "plugin/zlib_save=gz" altmove -uu testuser sentbefore 8d". I'm right thinking that it should work? I will really end with a primary uncompressed mail store and an alternate, zlib-compressed one?
Thank you all and sorry if I did some naive questions.
[1] 63c63 < G2fd0811c64be8e553d970000eaa8309f
G2ed0811c64be8e553d970000eaa8309f
-- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8
Sorry list, anyone with a good idea / suggestion?
Thanks.
Il 29-06-2015 11:20 Gionatan Danti ha scritto:
Hi all, any ideas?
Especially point n.1 (no hardlink when sending the same email to multiple addresses) confuse me a bit. Searching in old messages I even stumbled on some users stating that, using Dovecot LMTP server, they achieved what I want (one messagge, multiple hardlinks), but I am _already_ using LMTP with no avail...
Regards.
On 27/06/15 18:18, Gionatan Danti wrote:
Hi all, I have some questions about hardlinks, alternate storage and compression. I already scanned the list for related information and I have an idea of how things works, but I would like to have a definite answer.
System spec:
- CentOS 6.6 x64
- dovecot-2.0.9-8.el6_6.4.x86_64 RPM package/version
- sdbox mail store
About hardlinks: when sending the same message to two different recipients, I see that the two u.x files are created as two different files. Diffing them, I see that the only difference is a single char (see [1] for an example). My questions are: a) it is possible to tell dovecot to create a single file + a single hardlink (linkref=2)? As other IMAP servers support that features (eg: Cyrus, CommunigatePro, etc) I am wondering if I missed something in configuring dovecot... b) If it is not possible, can I run a script that compare the various files and substitute equal ones (minus the changing line) with hardlinks, or it will confuse dovecot? As a side note, why the changing line ever exists?
About alternate storage and compression: actually, I use a single mail_location without compression. I would like to have an alternate storage and to enable compression on it only, leaving the main location without compression. I if understand it correctly, it _should_ be done using a command similar to "doveadm -Dv -o "plugin/zlib_save=gz" altmove -uu testuser sentbefore 8d". I'm right thinking that it should work? I will really end with a primary uncompressed mail store and an alternate, zlib-compressed one?
Thank you all and sorry if I did some naive questions.
[1] 63c63 < G2fd0811c64be8e553d970000eaa8309f
G2ed0811c64be8e553d970000eaa8309f
-- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8
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Gionatan Danti