[Ocfs2-users] Ofcs2 Questions!

Thu Feb 3 11:00:19 PST 2011

So you are using only one imap server ? And only if it fails the other one
assumes ? Don't you have any balancer ?

How is the backup of that data ? As i said, is really slow the backup here.

The use of this 6gb ram, how much it is cached ? Or all 6gb are used by
mailscaner postfix and dovecot ?

Sorry ask that many questions.

In my system, 1.5 GB is more than enough for dovecot mailscanner and
postfix.

[]'sf.rique

2011/2/3 Antonis Kopsaftis <akops at edu.teiath.gr>

>  Hello,
>
> My setup consists with 2 backend mail servers, running
> dovecot/postfix/mailscanner in primary/secondary mode. The primary server
> has 6GB ram, and the seconadary a virtual machine with 2GB ram. Both servers
> using a external SAN over fiber. I have over 15.000users, and the
> performance is very good without using any exotic performance tips. I just
> mount the filesystem with noatime. I ran this setup for almost a year
> without any problems.
> After the discovery of the bug that ocfs2 has last October , and the
> notification from oracle people, that the bug will not be fixed, i searched
> for an alternative filesystem.
> So during December i moved all my user files to gfs2. On the same setup
> gfs2 is a little slower than ocfs2.
>
> I have another cluster (not mail) running with ocfs2. Sadly i have to
> change that too...
>
> Regards,
> akops
>
>
>
>
>
>
> On 3/2/2011 7:45 μμ, Henrique Fernandes wrote:
>
> I just read some, the problems is it will be to difficult to us to migrate
> it now. Because they migrate into ocfs2 quite recently.
>
> No other docs for performance improvement for maildir ?
>
> []'sf.rique
>
>
> On Thu, Feb 3, 2011 at 4:40 AM, Antonis Kopsaftis <akops at teiath.gr> wrote:
>
>>  Hello,
>>
>> You should read the archives of this list on Oct/Nov 2010. The ocfs2 1.4
>> has the  "No space left on device error" bug which (according to oracle
>> people on this list) will
>> not be fixed, as the 2.6.18 kernel that centos 5.x  has is very very old.
>> You can try to install the  Unbreakable Kernel from oracle, but dont count
>> on it. I tried it and  my system was pretty messed up
>>
>> I was using ocfs2 with a setup pretty like
>> yours(dovecot/qmail/mailscanner) in production, and it worked very well, but
>> because of the bug, i had to switch to another
>> filesystem, althought i was happy with ocfs2.
>>
>> akops
>>
>>
>>
>> On 3/2/2011 3:10 πμ, Henrique Fernandes wrote:
>>
>> centos 5.5
>> ocfs2 1.4
>> The mail solution, dovecot+postifx+mailscaner  uses about 1 gb the machine
>> has 1.5 in my tests i am rising it to 3gb so it have 2gb of cached
>>
>> How many memory do you thing i should separeted for cache ?
>>
>> When we made some tests  ocfs2 1.4 had better performance than 1.6 but or
>> tests were very simple, an script that writes lots of files and anothe rone
>> that reads it.
>>
>> And it is a problem to have ocfs2 1.6 in ths centos!!
>>
>> Should i use ocfs2 in production ?
>>
>> how about the commit and noatime configs ??
>>
>>
>> thanks!!
>>
>> []'sf.rique
>>
>>
>> On Wed, Feb 2, 2011 at 9:27 PM, Sunil Mushran <sunil.mushran at oracle.com>wrote:
>>
>>>  version? distro?
>>>
>>> This workload will benefit a lot with the indexed directories available
>>> in
>>> ocfs2 1.6 (and mainline and sles11).
>>>
>>> The other thing to check is the amount memory in the virtual machines.
>>> File systems need memory to cache the inodes. If memory is lacking,
>>> the inodes are freed and have to be re-read from disk time and again.
>>> While this is a problem even in a local fs, it is a bigger problem in a
>>> cfs
>>> as a cfs needs to do lock mastery for the same inode time and again.
>>>
>>>
>>> On 02/02/2011 01:09 PM, Henrique Fernandes wrote:
>>>
>>>  Hello,
>>>
>>> First of all, i am new at the list and i have several questions about
>>> ocfs2 performance.
>>>
>>> Where i am working i am having huge performance problens with ocfs2.
>>>
>>> Let me tell my envoriment.
>>>
>>> 3 Xen VirtualMachines withs ocfs2 mounting an LUN exported over iSCSI. (
>>> acctualy 3 LUNS, 3 ocfs2 clusters )
>>>
>>> I am not the one who configured the envoriment, but it is making the
>>> performance of my MAIL system to bad.
>>>
>>> Have about 9k accounts but only 4k are active. It is a maildir system. (
>>> postfix + dovecot )
>>>
>>> Now that this performance problens are afecting my system i am gonna try
>>> help to tunning the ocfs2.
>>>
>>> Pretty much all default settings.
>>>
>>> OCFS2 is configured to write with ordered mode. We know that changing to
>>> writeback will make performance much better, but we are not considering lose
>>> anydata, so it i snot an option.
>>>
>>> Now we are going to implemente noatime options in mount. This make better
>>> performace ?
>>>
>>> Other one, how about the commit mount options ? The default is set to 5s
>>> if i increse it how is the potential data loss in case we lost lose power?
>>>
>>> Does anyone have any other paramenter that should help us ?
>>>
>>> Another info, the inscremental backup is taking 10 to 12 hours.
>>>
>>> All nodes have VERY high I/O wait.
>>>
>>> Thanks to all!!
>>>
>>> If you could tell me any doc that i sould read would be nice to!
>>>
>>>
>>>
>>>
>>>
>>>
>>> []'sf.rique
>>>
>>>
>>> _______________________________________________
>>> Ocfs2-users mailing listOcfs2-users at oss.oracle.comhttp://oss.oracle.com/mailman/listinfo/ocfs2-users
>>>
>>>
>>>
>>
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>>
>>
>>  --
>>
>> ============================================================
>>     ____________
>>    | __________ |\\ .....................................
>>    ||    0 0   || | . . Κοψαύτης Αντώνης              . .
>>    ||     J    || | . . System Administrator          . .
>>    ||   [___]  || | . . Κέντρο Διαχείρισης Δικτύου    . .
>>    ||__________|| | . . ΤΕΙ Αθήνας                    . .
>>    | __________ | | . . 210-5385790                 . .
>>    | ______==== | | . . akops at teiath.gr               . .
>>    | __________ | | . . VMware Certified Professional . .
>>    |____________|/  .....................................
>>
>> =============================================================
>>
>>
>>
>
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