[gfarm-discuss:07032] Re: gfrep replication question

[Osamu Tatebe <tatebe@xxxxxxxxxxxxxxxx>]

Hi Dave,

Currently, we use an invalidation-based protocol to
keep consistency among file replicas.  This means when
you modify a file, every other file replicas are deleted.
To create file replicas, you need to execute gfrep again.

Also, when you create a new file, you need to re-run gfrep
to create copies.

BTW, gfarmfs-fuse version 2.0.0 will be out soon.  It includes
-N #copy option.  If you mount by 'gfarmfs -N2 mount_dir',
any new file will be replicated in background.  In this case,
you do not need to run gfrep explicitly to create copies.

Thanks,
Osamu

On Wed, 28 Feb 2007 12:40:19 -0000 "David Whitehouse" <David.Whitehouse@xxxxxxxxx> wrote:

> Is it possible to clarify my understanding of file replication in gfarm.
> 
>  
> 
> I understand that by using the gfrep command, I can create file replicas
> across filenodes. However what I am not clear about is the
> synchronisation of these files.
> 
>  
> 
> After I have created a replica, will the file copies be automatically
> kept in sync' or do I need to regularly run the gfrep command to update
> any changes to all file replicas?
> 
>  
> 
> Also, if I have run the gfrep command against a directory previously,
> will any new files in this directory be automatically replicated or do I
> need to re-run gfrep to create copies of any new files.
> 
>  
> 
> Thanks and regards
> 
> Dave.
>  
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