[Ocfs2-users] Please urgent help required - OCFS2 and VPN again

[Sunil Mushran]

Could be. Say it needs to get the appropriate locks before
it can read the file. In that case, the latency will be a big factor.

Read the notes section in the 1.4 user's guide. It attempts to
explain how the fs works.

Lorenzo Milesi wrote:
> I suppose rsync takes ages in reading all directory tree and directory
> listing, as it has to dig it all!
> This shouldn't be affected by drbd "writes", isn't it? Is it due to high
> latency?
>
> thanks!
>
>
> Il giorno lun, 08/12/2008 alle 17.15 -0800, Sunil Mushran ha scritto:
>   
>> ocfs2 does not have a concept of "primary". While we do use
>> lower node number as a tie breaker in the dlm, that in itself
>> should not be affect the performance much.
>>
>> See what rsync is doing.
>>
>> Lorenzo Milesi wrote:
>>     
>>> Thanks again.
>>>
>>> Another curiosity: as I told we have a rsync backup running on one node.
>>> If that node is set "primary" (node number 0 in cluster.conf) that rsync
>>> takes up to 4h for transferring very few files, while if I set it
>>> "secondary" it takes 20m!
>>>
>>>
>>>
>>> Il giorno lun, 08/12/2008 alle 12.33 -0800, Sunil Mushran ha scritto:
>>>   
>>>       
>>>> ocfs2's interconnect usage is latency sensitive. It does not use
>>>> much bandwidth. While it has small packets, it has lots of them.
>>>> It has been written with a low latency gige private interconnect
>>>> in mind.
>>>>
>>>> In your setup you are using drbd which is replicating all block
>>>> writes across the interconnect. That is bandwidth sensitive.
>>>>
>>>> The performance of the ocfs2 file system (all fses actually) is partly
>>>> dependant on the underlying block device. If the block device is
>>>> slow, the overall performance of the fs will be slow.
>>>>
>>>> Lorenzo Milesi wrote:
>>>>     
>>>>         
>>>>> Il giorno mar, 02/12/2008 alle 12.11 -0800, Sunil Mushran ha scritto:
>>>>>   
>>>>>       
>>>>>           
>>>>>> The interconnect is your bottleneck.
>>>>>>     
>>>>>>         
>>>>>>             
>>>>> thanks for your answer. what could be the minimum bandwidth for letting
>>>>> ocfs2 work fine?
>>>>>
>>>>> thanks
>>>>>
>>>>>   
>>>>>       
>>>>>           
>>>>     
>>>>         
>>