[Gluster-users] gfid generation

Pranith Kumar Karampuri pkarampu at redhat.com
Wed Nov 16 05:45:18 UTC 2016


On Wed, Nov 16, 2016 at 3:31 AM, Ankireddypalle Reddy <areddy at commvault.com>
wrote:

> Kaushal/Pranith,
>                                   Thanks for clarifying this. As I
> understand there are 2 id's. Please correct if there is a mistake in my
> assumptions:
>                                   1) HASH generated by DHT and this will
> generate the same id for a given file all the time.
>                                   2) GFID which is an version 4 UUID. As
> per the below links this is supposed to contain a time stamp field in it.
> So this will not generate the same id for a given file all the time.
>                                        https://en.wikipedia.org/wiki/
> Universally_unique_identifier
>                                        https://tools.ietf.org/html/rfc4122


That is correct. There is no involvement of parent gfid in either of this
:-).


>
>
> Thanks and Regards,
> ram
> -----Original Message-----
> From: Kaushal M [mailto:kshlmster at gmail.com]
> Sent: Tuesday, November 15, 2016 1:21 PM
> To: Ankireddypalle Reddy
> Cc: Pranith Kumar Karampuri; gluster-users at gluster.org; Gluster Devel
> Subject: Re: [Gluster-users] gfid generation
>
> On Tue, Nov 15, 2016 at 11:33 PM, Ankireddypalle Reddy <
> areddy at commvault.com> wrote:
> > Pranith,
> >
> >                  Thanks for getting back on this. I am trying to see
> > how gfid can be generated programmatically. Given a file name how do
> > we generate gfid for it. I was reading some of the email threads about
> > it where it was mentioned that gfid is generated based upon parent
> > directory gfid and the file name. Given a same parent gfid and file
> > name do we always end up with the same gfid.
>
> You're probably confusing the hash as generated for the elastic hash
> algorithm in DHT, with UUID. That is a combination of
>
> I always thought that the GFID was a UUID, which was randomly generated.
> (The random UUID might be being modified a little to allow some leeway with
> directory listing, IIRC).
>
> Adding gluster-devel to get more eyes on this.
>
> >
> >
> >
> > Thanks and Regards,
> >
> > ram
> >
> >
> >
> > From: Pranith Kumar Karampuri [mailto:pkarampu at redhat.com]
> > Sent: Tuesday, November 15, 2016 12:58 PM
> > To: Ankireddypalle Reddy
> > Cc: gluster-users at gluster.org
> > Subject: Re: [Gluster-users] gfid generation
> >
> >
> >
> > Sorry, didn't understand the question. Are you saying give a file on
> > gluster how to get gfid of the file?
> >
> > #getfattr -d -m. -e hex /path/to/file shows it
> >
> >
> >
> > On Fri, Nov 11, 2016 at 9:47 PM, Ankireddypalle Reddy
> > <areddy at commvault.com>
> > wrote:
> >
> > Hi,
> >
> >         Is the mapping from file name to gfid an idempotent operation.
> > If so please point me to the function that does this.
> >
> >
> >
> > Thanks and Regards,
> >
> > Ram
> >
> > ***************************Legal Disclaimer***************************
> >
> > "This communication may contain confidential and privileged material
> > for the
> >
> > sole use of the intended recipient. Any unauthorized review, use or
> > distribution
> >
> > by others is strictly prohibited. If you have received the message by
> > mistake,
> >
> > please advise the sender by reply email and delete the message. Thank
> you."
> >
> > **********************************************************************
> >
> >
> > _______________________________________________
> > Gluster-users mailing list
> > Gluster-users at gluster.org
> > http://www.gluster.org/mailman/listinfo/gluster-users
> >
> >
> >
> >
> > --
> >
> > Pranith
> >
> > ***************************Legal Disclaimer***************************
> > "This communication may contain confidential and privileged material
> > for the sole use of the intended recipient. Any unauthorized review,
> > use or distribution by others is strictly prohibited. If you have
> > received the message by mistake, please advise the sender by reply
> > email and delete the message. Thank you."
> > **********************************************************************
> >
> > _______________________________________________
> > Gluster-users mailing list
> > Gluster-users at gluster.org
> > http://www.gluster.org/mailman/listinfo/gluster-users
> ***************************Legal Disclaimer***************************
> "This communication may contain confidential and privileged material for
> the
> sole use of the intended recipient. Any unauthorized review, use or
> distribution
> by others is strictly prohibited. If you have received the message by
> mistake,
> please advise the sender by reply email and delete the message. Thank you."
> **********************************************************************
>



-- 
Pranith
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20161116/89ca59e9/attachment.html>


More information about the Gluster-users mailing list