Poor Roundcube performance with default configuration

[Enrico Tagliavini]

Why for ext2 and ext3 you should be able to disable it? They are no
special when it comes to power loss. Yes the commit is forced every 5
seconds, and that's more than enough to corrupt stuff.

Other than that I would keep the sync enabled anyway since you might
have a battery backed cache on the drive / controller, but if the
write cache of your OS file system is lost well that's still not good.
What you can turn off to increase performance, if you have a battery
backed cache, are block level write barriers.

However what I'm saying is valid in general, no idea if cyrus-imapd
ensures some level on consistency by other means (like calling fsync()
when needed instead of doing every single write in sync mode). But I
still can't see any way why ext2 and ext3 would let you disable the
sync safely.

Best regards.
Enrico

On 3 February 2015 at 16:23, Christian Hügel
<christian.huegel at stonebyte.de> wrote:
> The issue with the poor performance is the "Synchronous File Operations" [1]
> For a ext2/ext3 file system you can turn this off
>
>
> [1] https://docs.kolab.org/administrator-guide/tweaking-cyrus-imapd.html
>
>
>
> Am 17-03-2014 21:27, schrieb Christian Hügel:
>>
>> This is the same observation I have made with roundcube [1] I even went
>> so far installing a imapproxy to improve somehow the webinterface.
>>
>>
>> [1] http://lists.kolab.org/pipermail/users/2013-December/016164.html
>>
>> Am 17.03.2014 21:12, schrieb Brady, Mike:
>>>
>>> Mileage may well vary on this one but I thought that others may be
>>> interested in this observation.
>>>
>>> With a default configuration of Kolab 3.1 on a single Centos 6.5 box I
>>> have found Roundcube performance to be not great.
>>>
>>> By default configuration I mean nothing more than
>>>
>>> yum install kolab
>>> setup-kolab
>>>
>>> has been done.
>>>
>>> I have found that disabling imap_cache and messages_cache significantly
>>> improves Roundcube performance.  These settings can be found in
>>> /etc/roundcube/config.inc.php.  I notice that what I assume to be the
>>> Roundcube defaults in /etc/roundcube/defaults.inc.php is for these to be
>>> disabled.
>>>
>>> Tuning mysql (which I haven't done) may well improve things, but I have
>>> to wonder if it is worth the additional overhead of running a mysql
>>> cache for Roundcube with a default all in one installation of the Kolab
>>> components?
>>>
>>> Thoughts?
>>>
>>> Regards
>>>
>>> Mike
>>> _______________________________________________
>>> users mailing list
>>> users at lists.kolab.org
>>> https://lists.kolab.org/mailman/listinfo/users
>>
>>
>>
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