[Gluster-devel] more details about "No metadata dependencies" ??

[Raghavendra G]

2009/7/31 Yi Ling <lingyi.pro at gmail.com>:
>
>
> 2009/7/31 Harald Stürzebecher <haralds at cs.tu-berlin.de>
>>
>> Hello!
>>
>> 2009/7/31 Yi Ling <lingyi.pro at gmail.com>:
>> > there is a section about metadata on page
>> > http://www.gluster.com/news.php
>> >
>> > "No metadata dependencies - metadata management is frequently a source
>> > of
>> > performance bottlenecks, particularly when there are a very large number
>> > of
>> > files, and can be a single point of failure in traditional file systems.
>> > GlusterFS eliminates this problem with intelligent data placement, an
>> > automatic data distribution method that optimizes the use of resources
>> > and
>> > eliminates metadata bottlenecks."
>> >
>> > yes,it's a advantage of GlusterFS. but yet i found no more detailed
>> > information about the "intelligent data placement" "an automatic data
>> > distribution methed". could anyone explain it in detail? and something
>> > about
>> > file managemment~~~
>>
>> AFAIK, the GlusterFS metadata is stored as extended attributes to the
>> files in the underlying filesystem.
>>
>> Hints can be found here:
>>
>>
>> http://www.gluster.org/docs/index.php/Understanding_AFR_Translator#Locking_and_Change_Log
>>
>>
>> http://www.gluster.org/docs/index.php/Setting_up_AFR_on_two_servers_with_pre-existing_data#Preparing_the_directories
>>
>>
>> Harald Stürzebecher
>
> thanks for replying~~ but im still confused~~~
>
> in client, what's the routine of an operation like "create"/"read" ,from
> client to server (even backend filesystem)?
>
> "the GlusterFS metadata is stored as extended attributes to the files in the
> underlying filesystem"
> well, after storing, how could i read the file and how to know where the
> file is located (or which server/brick the file is stored)

Distribute Translator provides the functionality of aggregating the
storage from individual nodes and giving the unified view of the total
storage. It stores the layout (which says, which file goes into which
node) of the directory in extended attributes of the directory. And
directories are created on all the nodes. Files are created on only
one of the nodes.

>
>
> _______________________________________________
> Gluster-devel mailing list
> Gluster-devel at nongnu.org
> http://lists.nongnu.org/mailman/listinfo/gluster-devel
>y
>


regards,
-- 
Raghavendra G