[Dovecot] Best Cluster Storage

[Henrique Fernandes]

[]'sf.rique


On Fri, Jan 21, 2011 at 4:31 PM, Ed W <lists at wildgooses.com> wrote:

> On 21/01/2011 17:50, Henrique Fernandes wrote:
>
>> I don't know if i got your question right, but before, while using mbox,
>> we had less users and much less quota, it was only 200MB now is about 1GB.
>>  And before we did not have a good backup system, had many problens.
>> We pretty much change to maildir to be easie to make incremental backups
>> and etc.
>>
>
> Sorry, the point of the question was simply whether you could use your old
> setup to help estimate whether there is actually any point switching from
> maildir?  Sounds like you didn't have the same backup service back then, so
> you can't compare though?
>

I am not comparin anything, because we reformulate ALL email system, before
it was only one machine with local disk. So we bougth an EMC and starting
using it to the new mail system in virtual machines iSCSI etc.

>
> Just pointing out that it's completely unproven whether moving mdbox will
> actually make a difference anyway...
>
>
>  And we are considering testing mbdox or sdbox. But still to earlier to
>> make another big change like this.
>>
>>
> Sure - by the way I believe you can mix mailbox storage formats to a large
> extent?  I'm not using this stuff so please check the docs before believing
> me, but I believe you can mix storage formats even down to the folder level
> under some conditions?  I dare say you did exactly this during your
> migration so I doubt I'm telling you anything new...?
>

Yeah i did likely you said, mix of mbox and maildir, actulay only active
users have maildir, inactive users still mbox.


>
> The only point of mentioning that is that you could do something as simple
> as duplicating some proportion of the mailboxes to new "dummy" accounts,
> simply for the purpose of padding out some new format directories - users
> wouldn't really access them.  Then you could try and compare the backup
> times of the original mailboxes (that the users actually use) with the
> duplicated ones in whatever format you are testing?
>
> Just an idea?
>
> We usualy use one domain per test. Like this other sdb1 we are testing.



> Good luck
>
> Ed W
>
>

But you asked before about haardware.

It is an EMC CX4, linked with ONE 1gbE to ONE dlink ( i am not sure but i
guess if full Gbit ) and from this dlink it conects to 4 XEN machines at
1gbit and in the virtual machines over iSCSI to EMC.

About the disk is 8 disk in RAID 1+0  in sda
and i guess in sdc and sdb is RAID5 with 12 disk ( those are test )

Sorry don't know spec form the disks.


We think it is the ocfs2 and the size of the partition, becasue. We can
write an big file in a accetable speed. But if we try to delete or create or
read lots of small files the speed is  horrible. We think is an DLM problem
in propagate the locks and etc.


Do you have any idea how to test the storage from maildir usage ? We made a
bashscript that write some diretores and lots of files and after it removes
and etc.

Any better ideias ?

Apreciate your help!