Mailing-List: contact cygwin-help AT sourceware DOT cygnus DOT com; run by ezmlm
Sender: cygwin-owner AT sourceware DOT cygnus DOT com
Delivered-To: mailing list cygwin AT sourceware DOT cygnus DOT com
Message-ID: <19990611231411.2648.rocketmail@web118.yahoomail.com>
Date: Fri, 11 Jun 1999 16:14:11 -0700 (PDT)
From: Earnie Boyd <earnie_boyd AT yahoo DOT com>
Reply-To: earnie_boyd AT yahoo DOT com
Subject: Re: cygwin tar to tape?
To: FAQ Maintainter <cygwin AT sourceware DOT cygnus DOT com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii


You may want to add this to the FAQ for the B21 release.

--- Corinna Vinschen <corinna AT vinschen DOT de> wrote:
> James Dumser wrote:
> > 
> > I've been experimenting with tape support under WinNT with your
> > "unofficial" cygwin1.dll. I tarred up some files on a Sun Ultra (running
> > Solaris), but when I tried to read it under cygwin, I get "permission
> > denied." I also tried the other way: create a tape under cygwin and read
> 
> You get this `permission denied' when you try to read a tape, that is
> written with another blocking factor than the Windows tape driver is set to.
> Windows has no automatical recognition for this!!!
> 
> You must(!) know the blocking (U*Xes typically uses 5K blocking) and
> you have to set it with my `mt' command from ftp site
> 
>
ftp://ftp.franken.de/pub/win32/develop/gnuwin32/cygwin/porters/Vinschen_Corinna/B20
> 
> to set blocksize to e.g. 5K:
> 
> 	mt setblk 5120
> 
> > it on the Ultra. (I'm using GNU tar on both machines.) When I do this,
> > tar (on the Ultra) reports a blocking factor of 1 (even though I
> > specified a blocking factor of 100 when wrote the tape), and reading is
> > incredibly slow.
> 
> The default blocksize under NT is 512 Bytes. It's a `feature' of Windows.
> Use my `mt' command from ftp site
> 
>
ftp://ftp.franken.de/pub/win32/develop/gnuwin32/cygwin/porters/Vinschen_Corinna/B20
> 
> to set blocksize to e.g. 5K once:
> 
> 	mt setblk 5120
> 
> But be warned! Another `oh so wunderful feature' of Windows is, that
> you only may set blocksize, if a tape is in the drive!!!
> 
> You may also use my patched `tar' from the same site. This tar sets the
> blocksize by itself to a default of 10K unless you use the -b option
> to set your own blocksize.
> 
> Same convenience with patched `cpio' from the same site, which sets blocksize
> to e.g. 5K if you use the -B option.
> 
> Another hint:
> All this only has an effect, if the tape driver supports setting blocksize!
> I know it works for the DDS driver which is part of NT 4.0 distribution.
> Older tape drives may use fixed blocksizes.
> 
> Regards,
> Corinna
> 
> -- 
> new mail address:
> mailto:corinna AT vinschen DOT de
> 
> --
> Want to unsubscribe from this list?
> Send a message to cygwin-unsubscribe AT sourceware DOT cygnus DOT com
> 
> 

===
YAWIA,
Earnie Boyd <mailto:earnie_boyd AT yahoo DOT com>

Newbies, please visit
<http://www.freeyellow.com/members5/gw32/index.html>
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com


--
Want to unsubscribe from this list?
Send a message to cygwin-unsubscribe AT sourceware DOT cygnus DOT com