Gluster users - Mar 2009 - Enterprise Application with O_DIRECT access

Hello everyone,

I am learning and evaluating a glusterfs for film/video editing facilities.
Some major film/video editing realtime applications are using the
O_DIRECT file access for video/audio data files.
The GLFS client via fuse mechanism is disallow the open file with
O_DIRECT flag.
I made a little sample code for read a file with O_DIRECT flag, and
tried open the files on GLFS volumes.
It returned "invalid arg" when open the file. It is OK when open the
file without O_DIRECT flag.

Is there a reason to have to refuse Direct I/O by the application though
it seems to use Direct I/O internally of GLFS?

Does someone have a problem same as me?
Let me know if you have any advise,plan in future or patch on this.

And, regarding the block size in fuse, I tried the optimization the
block size in client side for film/video applications.
When it was increased, the performance results is good.
I think that it is convenient if it can change the block size in mount
options.
What do you think?

Regards,

Hideo.

With glusterfs patched fuse you should be able to work fine with O_DIRECT
flag. The default stock kernel module doesn't support it.

Yes, by increasing the blocksize of the filesystem, few application
performance will increase significantly.

Regards,
Amar

On Tue, Mar 10, 2009 at 10:52 PM, Hideo Umemura(Max-T)
<h.umemura at max-t.jp>wrote:
> Hello everyone,
>
> I am learning and evaluating a glusterfs for film/video editing facilities.
> Some major film/video editing realtime applications are using the
> O_DIRECT file access for video/audio data files.
> The GLFS client via fuse mechanism is disallow the open file with
> O_DIRECT flag.
> I made a little sample code for read a file with O_DIRECT flag, and
> tried open the files on GLFS volumes.
> It returned "invalid arg" when open the file. It is OK when open
the
> file without O_DIRECT flag.
>
> Is there a reason to have to refuse Direct I/O by the application though
> it seems to use Direct I/O internally of GLFS?
>
> Does someone have a problem same as me?
> Let me know if you have any advise,plan in future or patch on this.
>
> And, regarding the block size in fuse, I tried the optimization the
> block size in client side for film/video applications.
> When it was increased, the performance results is good.
> I think that it is convenient if it can change the block size in mount
> options.
> What do you think?
>
> Regards,
>
> Hideo.
>
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://zresearch.com/cgi-bin/mailman/listinfo/gluster-users
>
>

-- 
Amar Tumballi
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