Re: [Ocfs2-users] Ofcs2 Questions!

[Sunil Mushran]

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


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Re: [Ocfs2-users] Ofcs2 Questions!

[Henrique Fernandes]

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 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@oss.oracle.comhttp://oss.oracle.com/mailman/listinfo/ocfs2-users
>
>
>
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Re: [Ocfs2-users] Ofcs2 Questions!

[Sunil Mushran]

# grep "Resources" /sys/kernel/debug/o2dlm/UUID/dlm_state
Lock Resources: 20713 (1139459)

The first number is number of live resources. Second the number
of resources created for the life of the domain.

If you see the the number of resources levelling off but the second
number incrementing, that _could_ mean that you could benefit with
a larger cache. But you have to supplement that number with the
workload. Say you are deleting and creating files. In that case, you
will see the same number movement but not because of the cache limit.

We are in the process of adding more counters to provide more visibility
to the users.

Well, using any software without support has its risks.

Using noatime will help. Increasing commit will help if workload if largely
from one node only.

On 02/02/2011 05:10 PM, 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 mailto:sunil.mush...@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


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Ocfs2-users@oss.oracle.com  
http://oss.oracle.com/mailman/listinfo/ocfs2-users





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Re: [Ocfs2-users] Ofcs2 Questions!

[Henrique Fernandes]

Thanks for the tips.

So you are saying that if both nodes have same load, inscrease comit time
will not make any diferences ?



[]'sf.rique


On Wed, Feb 2, 2011 at 11:54 PM, Sunil Mushran wrote:

>  # grep "Resources" /sys/kernel/debug/o2dlm/UUID/dlm_state
> Lock Resources: 20713 (1139459)
>
> The first number is number of live resources. Second the number
> of resources created for the life of the domain.
>
> If you see the the number of resources levelling off but the second
> number incrementing, that _could_ mean that you could benefit with
> a larger cache. But you have to supplement that number with the
> workload. Say you are deleting and creating files. In that case, you
> will see the same number movement but not because of the cache limit.
>
> We are in the process of adding more counters to provide more visibility
> to the users.
>
> Well, using any software without support has its risks.
>
> Using noatime will help. Increasing commit will help if workload if largely
> from one node only.
>
>
> On 02/02/2011 05:10 PM, 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 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@oss.oracle.comhttp://oss.oracle.com/mailman/listinfo/ocfs2-users
>>
>>
>>
>
>
___
Ocfs2-users mailing list
Ocfs2-users@oss.oracle.com
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Re: [Ocfs2-users] Ofcs2 Questions!

[Sunil Mushran]

It shouldn't. But I have been known to be wrong before.
And testing with different commit values is easy enough.

On 02/02/2011 06:03 PM, Henrique Fernandes wrote:

Thanks for the tips.

So you are saying that if both nodes have same load, inscrease comit time will 
not make any diferences ?



[]'sf.rique


On Wed, Feb 2, 2011 at 11:54 PM, Sunil Mushran mailto:sunil.mush...@oracle.com>> wrote:

# grep "Resources" /sys/kernel/debug/o2dlm/UUID/dlm_state
Lock Resources: 20713 (1139459)

The first number is number of live resources. Second the number
of resources created for the life of the domain.

If you see the the number of resources levelling off but the second
number incrementing, that _could_ mean that you could benefit with
a larger cache. But you have to supplement that number with the
workload. Say you are deleting and creating files. In that case, you
will see the same number movement but not because of the cache limit.

We are in the process of adding more counters to provide more visibility
to the users.

Well, using any software without support has its risks.

Using noatime will help. Increasing commit will help if workload if largely
from one node only.


On 02/02/2011 05:10 PM, 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 mailto:sunil.mush...@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


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http://oss.oracle.com/mailman/listinfo/ocfs2-users








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Re: [Ocfs2-users] Ofcs2 Questions!

[Henrique Fernandes]

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  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 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@oss.oracle.comhttp://oss.oracle.com/mailman/listinfo/ocfs2-users
>>
>>
>>
>
> ___
> Ocfs2-users mailing 
> listOcfs2-users@oss.oracle.comhttp://oss.oracle.com/mailman/listinfo/ocfs2-users
>
>
> --
>
> 
> 
>| __ |\\ .
>||0 0   || | . . Κοψαύτης Αντώνης  . .
>|| J|| | . . System Administrator  . .
>||   [___]  || | . . Κέντρο Διαχείρισης Δικτύου. .
>||__|| | . . ΤΕΙ Αθήνας. .
>| __ | | . . 210-5385790 . .
>| __ | | . . ak...@teiath.gr   . .
>| __ | | . . VMware Certified Professional . .
>||/  .
>
> =
>
>
>
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Re: [Ocfs2-users] Ofcs2 Questions!

[Antonis Kopsaftis]

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  > 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
>> mailto:sunil.mush...@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

Re: [Ocfs2-users] Ofcs2 Questions!

[Henrique Fernandes]

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 

>  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  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 
>> 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 

Re: [Ocfs2-users] Ofcs2 Questions!

[Sérgio Surkamp]

Em Thu, 3 Feb 2011 15:45:31 -0200
Henrique Fernandes  escreveu:

> 
> No other docs for performance improvement for maildir ?
> 

Dovecot and courier has its own Maildir extensions called Maildir++.

http://www.inter7.com/courierimap/README.maildirquota.html
http://wiki.dovecot.org/MailboxFormat/Maildir

The main feature that improves performance is the ",S={size}" extension
on the Maildir's files name specification. That prevents the quota
system (or IMAP/POP3 daemons) to stat(2) every file to known its size
when reading the Maildir (or Maildir folder) contents.

Is your maildrop Maildir++ complaint? If you are using the default
postfix maildrop (by setting home_mailbox = Maildir/), then it isn't
Maildir++ complaint.

http://www.postfix.org/postconf.5.html#mailbox_command
http://www.postfix.org/postconf.5.html#home_mailbox

Dovecot should provide a drop-in replacement for postfix's default
maildrop. http://wiki.dovecot.org/maildrop (I think this is the right
documentation about it).

Regards,
-- 
  .:':.
.:'` Sérgio Surkamp | Gerente de Rede
::   ser...@gruposinternet.com.br
`:..:'
  `:,   ,.:' *Grupos Internet S.A.*
`: :'R. Lauro Linhares, 2123 Torre B - Sala 201
 : : Trindade - Florianópolis - SC
 :.'
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