Thank you for that fine and detailed explanation...
My understanding is that hfstar is derived from gnutar, so I would
assume it preserves the gnutar behavior of not reading the files.
Does anyone know what happened to the "estimate" code for OS X?
It sounds like this could help a lot, and in my case, accuracy of the
estimate is not much of an issue...
Thanks again,
Dick
> rwk AT americom DOT com wrote:
> > Has anyone else experienced long estimates using amanda and hfstar on OS X?
> > Is there any way to improve the speed on this?
> > Why is it so slow when "dump" and "samba" are not?
>
> The way tar works is inherently slower then dump (or samba).
> Tar needs to "stat" each file it will backup. If there are many
> small files, and/or lots of directories, it can take a long time.
> During the estimate phase, tar is run with the option "--file /dev/null"
> and gnutar is optimised to not even try to read the files; it only
> collects the statistics if needed. I don't know if hfstar on OS X does
> the same.
> Dump bypasses the filesystem and reads the disk device, and as such
> can very quickly get an estimate; it does no "stat" on each file.
> Smbclient uses the builtin "du" command to get an estimate (only
> an estimate; exclude files are not processed).
>
> If it is really painfully slow, and I remember someone (Gerard?)
> one wrote a very fast "estimate" for his particular case (no
> subdirectories, only complete disks, no exclude file processing etc).
> I don't know what happened with the code...
>
>
>
> > P.S. At first I thought it didn't work at all, but I increased the
> > value of etimeout to 60 minutes and it then worked.
>
> You're still lucky, I once had a system where the estimate phase
> took 2 hours 40 minutes! (Sun Solaris 2.6 with 18 Gbyte filesystem
> with lots of small files. I moved the filesystem to a Linux box with
> reiserfs and now the estimate phase takes only 18 minutes; to be honest
> the content changed also a bit.)
>
>
>
> --
> Paul Bijnens, Xplanation Tel +32 16 397.511
> Technologielaan 21 bus 2, B-3001 Leuven, BELGIUM Fax +32 16 397.512
> http://www.xplanation.com/ email: Paul.Bijnens AT xplanation DOT com
> ***********************************************************************
> * I think I've got the hang of it now: exit, ^D, ^C, ^\, ^Z, ^Q, F6, *
> * quit, ZZ, :q, :q!, M-Z, ^X^C, logoff, logout, close, bye, /bye, *
> * stop, end, F3, ~., ^]c, +++ ATH, disconnect, halt, abort, hangup, *
> * PF4, F20, ^X^X, :D::D, KJOB, F14-f-e, F8-e, kill -1 $$, shutdown, *
> * kill -9 1, Alt-F4, Ctrl-Alt-Del, AltGr-NumLock, Stop-A, ... *
> * ... "Are you sure?" ... YES ... Phew ... I'm out *
> ***********************************************************************
>
>
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