Ok, thank you very much for all your efforts to help, greatly appreciated

Kind regards,

Henk

On Sep 12, 2013, at 2:07 PM, James Burton <[email protected]> wrote:

> rsync on the OSX is ancient (2.6.8), but it looks like rsync's poor 
> performance is expected. rsync is a much more complex program than cp or tee 
> or rcp or even scp. 
> 
> http://lwn.net/Articles/400489/
> 
> The advantage of rsync is that if a small number of files have changed in a 
> large set, then only the changed files need to be copied. But if the entire 
> dataset needs to be copied, the "smart copy" of rsync is going to be slower 
> than the "dumb copy" of cp. 
> 
> The multi-node propagation algorithm I posted earlier should work with any 
> local->remote copy utility. 
> 
> Jim
> 
> 
> On Thu, Sep 12, 2013 at 7:23 AM, Henk D. Schoneveld <[email protected]> 
> wrote:
> Did some testing and see some strange results. rsync being considerably 
> slower then cp or tee
> 
> time rsync /Network/sata3/samsara.2011.720p-50fps.m4v /Network/sata4/2632
> 
> real    6m10.834s
> user    0m8.299s
> sys     0m12.368s
> 
> time cp /Network/sata3/samsara.2011.720p-50fps.m4v /Network/sata4/2632
> 
> real    3m43.190s
> user    0m0.005s
> sys     0m5.349s
> 
> time tee < /Network/sata3/samsara.2011.720p-50fps.m4v > /Network/sata4/2632 
> /Network/sata2/2632
> 
> real    3m46.949s
> user    0m0.176s
> sys     0m20.299s
> 
> another rsync to show it's not a caching influence. On OSX Activity monitor 
> in Network I do clearly see that  Data sent is about the same as Data read 
> with rsync while with cp and tee it's about double write speed against single 
> speed read.
> 
> rm -f /Network/sata4/2632 /Network/sata2/2632;time rsync 
> /Network/sata3/samsara.2011.720p-50fps.m4v /Network/sata4/2632
> 
> real    6m4.532s
> user    0m8.138s
> sys     0m11.395s
> time rsync /Network/sata3/samsara.2011.720p-50fps.m4v /Network/sata2/2632
> 
> real    6m2.038s
> user    0m8.142s
> sys     0m11.478s
> 
> Source 100Mb/s rest are 3 1Gb/s systems. One system in the middle OSX, reads 
> at 12MB/s and writes at 24MB/s with cp and tee. With rsync it only writes at 
> ~ 11MB/s
> Maybe it's OSX version of rsync's fault but very strange.
> 
> Henk
> 
> On Sep 11, 2013, at 1:45 AM, Henk D. Schoneveld <[email protected]> wrote:
> 
> > That should work, but as I understand it there will be 4 threads running. 
> > Bandwith on source-server has to be shared between these threads.
> > What I'm dreaming of is some kind of broad- multicasting to 4 ip-adress to 
> > get max throughput.
> > Maybe it's impossible but would be very efficient wouldn't it ?
> >
> > Henk
> > On Sep 10, 2013, at 9:09 PM, James Burton <[email protected]> wrote:
> >
> >> Henk,
> >>
> >> rsync will mostly do what you want it to do, but rsync doesn't support 
> >> remote->remote copy.
> >>
> >> The way I do multi-node copies involves using a recursive copy algorithm 
> >> that uses ssh to run rsync on the remote machines. On each pass, every 
> >> node that has source copies to a node that doesn't, which quickly copies 
> >> the source to all the nodes in the list.
> >>
> >> Here is the psuedocode. Of course, rsync and ssh need to be set up 
> >> correctly on all the nodes and you have to be sure you are using the right 
> >> syntax for your application, but this is a basic idea of what to do.
> >>
> >> copyAll( nodes[] ):
> >>
> >> # assume source is at node[0]
> >>
> >> len = nodes.length()
> >>
> >> if len == 1: return
> >>
> >> # copy the source to node in the the middle of the list.
> >> ssh user@node[0] "rsync -a /path/to/files user@node[len/2]:/path/to/files"
> >>
> >> # partition the list and call recursively on separate threads
> >>
> >> # this copies from node[0]->node[len/4]
> >> thread(copyAll(nodes[0:len/2]))
> >>
> >> # this copies from node[len/2]->node[3*len/4]
> >> thread(copyAll(nodes[len/2:len]))
> >>
> >> Hope that helps.
> >>
> >> Jim
> >>
> >>
> >> On Tue, Sep 10, 2013 at 12:36 PM, Henk D. Schoneveld <[email protected]> 
> >> wrote:
> >>
> >> On Sep 10, 2013, at 4:56 PM, James Burton <[email protected]> wrote:
> >>
> >>> Henk,
> >>>
> >>> I'm not sure what you are trying to do.
> >>>
> >>> Are you looking to copy data from one server to a series of servers?
> >> Yes
> >>> Is this a one time copy for setup or will this be part of an ongoing 
> >>> system?
> >> It will be part of an ongoing system.
> >>>
> >>> Thanks,
> >>>
> >>> Jim
> >>>
> >>>
> >>> On Mon, Sep 9, 2013 at 4:25 PM, Henk D. Schoneveld <[email protected]> 
> >>> wrote:
> >>> Hi everybody,
> >>>
> >>> I'm thinking about installing 5 groups of 30 pvfs2-systems in a 100Mb/s 
> >>> WAN. The reason for this setup is that if one group would fail the 
> >>> remaining 4 groups will be able to serve the original amount of intended 
> >>> clients. IO-load would be 5/4 of the original setup.
> >>>
> >>> All groups share one 5Gb/s connection to the internet.
> >>>
> >>> To get minimal data transferred from the server somewhere on the internet 
> >>> I'm thinking about following scenario. Copy a file with 30x100Mb/s = 
> >>> 3Gb/s on 1 group and then parallel redistribute to the remaining groups.
> >>>
> >>> Any ideas how to do this most efficiently ? I know tee < source > dest0 
> >>> dest1 dest2 dest3 dest4 would do this but it's not recursively and 
> >>> wildcards aren't accepted. rsync works with wildcards and recursively but 
> >>> how to get it done parallel in a way that load on the source group is 
> >>> minimal ?
> >>>
> >>> Suggestions ver welcome
> >>>
> >>> Henk
> >>> _______________________________________________
> >>> Pvfs2-users mailing list
> >>> [email protected]
> >>> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
> >>>
> >>
> >>
> >
> >
> > _______________________________________________
> > Pvfs2-users mailing list
> > [email protected]
> > http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
> 
> 


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