Re: gfid generation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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
 
Thanks and Regards,
ram
-----Original Message-----
From: Kaushal M [mailto:kshlmster@xxxxxxxxx] 
Sent: Tuesday, November 15, 2016 1:21 PM
To: Ankireddypalle Reddy
Cc: Pranith Kumar Karampuri; gluster-users@xxxxxxxxxxx; Gluster Devel
Subject: Re:  gfid generation

On Tue, Nov 15, 2016 at 11:33 PM, Ankireddypalle Reddy <areddy@xxxxxxxxxxxxx> 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@xxxxxxxxxx]
> Sent: Tuesday, November 15, 2016 12:58 PM
> To: Ankireddypalle Reddy
> Cc: gluster-users@xxxxxxxxxxx
> Subject: Re:  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@xxxxxxxxxxxxx>
> 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@xxxxxxxxxxx
> 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@xxxxxxxxxxx
> 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."
**********************************************************************
_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
http://www.gluster.org/mailman/listinfo/gluster-users



[Index of Archives]     [Gluster Development]     [Linux Filesytems Development]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux