When to use "filestore xattr use omap = true"

When to use "filestore xattr use omap = true"

[Roberto Aguilar]

Hello,

I read the "Filesystems" section in the "Hard disk and file system
recommendations" [1] documentation and was confused on whether or not
I should be using the setting:

  filestore xattr use omap = true

The section reads:

"[...] but the ext4 is too small to be usable. To use these file
systems, you should add the following like to the [osd] section of
your ceph.conf file.:"

Does that mean I the setting applies to systems that are using ext4,
or does it apply to _any_ filesystem that was mentioned, i.e. btrfs,
xfs, and ext4.

Thanks!
-Roberto.

[1] http://ceph.com/docs/master/rados/configuration/filesystem-recommendations/

Re: When to use "filestore xattr use omap = true"

[Mark Nelson]

On 01/03/2013 03:16 PM, Roberto Aguilar wrote:
> Hello,
>
> I read the "Filesystems" section in the "Hard disk and file system
> recommendations" [1] documentation and was confused on whether or not
> I should be using the setting:
>
>    filestore xattr use omap = true
>
> The section reads:
>
> "[...] but the ext4 is too small to be usable. To use these file
> systems, you should add the following like to the [osd] section of
> your ceph.conf file.:"
>
> Does that mean I the setting applies to systems that are using ext4,
> or does it apply to _any_ filesystem that was mentioned, i.e. btrfs,
> xfs, and ext4.
>
> Thanks!
> -Roberto.
>
> [1] http://ceph.com/docs/master/rados/configuration/filesystem-recommendations/
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Hi Roberto,

You should always use "filestore xattr use omap = true" with EXT4.  You 
can optionally use it for BTRFS and XFS.  I've done a bit of testing and 
haven't yet been able to determine if there is any significant advantage 
or disadvantage to using it on BTRFS and XFS from a performance 
perspective.  So far the performance differences haven't been consistent 
or significant enough to be conclusive.

Mark

Re: When to use "filestore xattr use omap = true"

[Roberto Aguilar]

Thanks for clarifying, Mark.  I made a quick change to the docs:

https://github.com/rca/ceph/commit/37b57cdf0fdc5c03eeff3f5eb58ff4010ce581f6

Can I send you a pull request?

Thanks,
-Roberto.

On Thu, Jan 3, 2013 at 1:20 PM, Mark Nelson <mark.nelson@inktank.com> wrote:
> On 01/03/2013 03:16 PM, Roberto Aguilar wrote:
>>
>> Hello,
>>
>> I read the "Filesystems" section in the "Hard disk and file system
>> recommendations" [1] documentation and was confused on whether or not
>> I should be using the setting:
>>
>>    filestore xattr use omap = true
>>
>> The section reads:
>>
>> "[...] but the ext4 is too small to be usable. To use these file
>> systems, you should add the following like to the [osd] section of
>> your ceph.conf file.:"
>>
>> Does that mean I the setting applies to systems that are using ext4,
>> or does it apply to _any_ filesystem that was mentioned, i.e. btrfs,
>> xfs, and ext4.
>>
>> Thanks!
>> -Roberto.
>>
>> [1]
>> http://ceph.com/docs/master/rados/configuration/filesystem-recommendations/
>> --
>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>
> Hi Roberto,
>
> You should always use "filestore xattr use omap = true" with EXT4.  You can
> optionally use it for BTRFS and XFS.  I've done a bit of testing and haven't
> yet been able to determine if there is any significant advantage or
> disadvantage to using it on BTRFS and XFS from a performance perspective.
> So far the performance differences haven't been consistent or significant
> enough to be conclusive.
>
> Mark
>

Re: When to use "filestore xattr use omap = true"

[Dan Mick]

Thanks for the help, Roberto.  Sure, send a pull request.

On 01/03/2013 01:31 PM, Roberto Aguilar wrote:
> Thanks for clarifying, Mark.  I made a quick change to the docs:
>
> https://github.com/rca/ceph/commit/37b57cdf0fdc5c03eeff3f5eb58ff4010ce581f6
>
> Can I send you a pull request?
>
> Thanks,
> -Roberto.
>
> On Thu, Jan 3, 2013 at 1:20 PM, Mark Nelson <mark.nelson@inktank.com> wrote:
>> On 01/03/2013 03:16 PM, Roberto Aguilar wrote:
>>>
>>> Hello,
>>>
>>> I read the "Filesystems" section in the "Hard disk and file system
>>> recommendations" [1] documentation and was confused on whether or not
>>> I should be using the setting:
>>>
>>>     filestore xattr use omap = true
>>>
>>> The section reads:
>>>
>>> "[...] but the ext4 is too small to be usable. To use these file
>>> systems, you should add the following like to the [osd] section of
>>> your ceph.conf file.:"
>>>
>>> Does that mean I the setting applies to systems that are using ext4,
>>> or does it apply to _any_ filesystem that was mentioned, i.e. btrfs,
>>> xfs, and ext4.
>>>
>>> Thanks!
>>> -Roberto.
>>>
>>> [1]
>>> http://ceph.com/docs/master/rados/configuration/filesystem-recommendations/
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>
>>
>> Hi Roberto,
>>
>> You should always use "filestore xattr use omap = true" with EXT4.  You can
>> optionally use it for BTRFS and XFS.  I've done a bit of testing and haven't
>> yet been able to determine if there is any significant advantage or
>> disadvantage to using it on BTRFS and XFS from a performance perspective.
>> So far the performance differences haven't been consistent or significant
>> enough to be conclusive.
>>
>> Mark
>>
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>