problem with GNU tar on NT

[Paul Eggert]

> Date: Thu, 29 Mar 2001 09:46:36 -0600
> From: "Duane Morris (rat924)" <address@hidden>

> a. This involves files contained on ClearCase.
> b. Works fine if ClearCase Server is NT.
> c. Does not work right if ClearCase Server is on Unix using TAS
> (totalnet by LSILogic).  Which is the case here.
> d. If we do the tar manually the tar works.  But if we run it from a
> script, using gmake and gtar on the NT side is when it fails.

This make it sound like it might be a bug in the NT port of GNU tar,
i.e. it's not a bug in the portable part of the tar code (which is
what I maintain), but somewhere in the NT port (which someone else
maintains -- sorry, I don't know who).  I'll CC: this to
address@hidden to see whether anyone with NT experience can help.

> Is there a option I can specify for the number of open file descriptors
> for gtar?

No, that's normally an option that is specified by the shell that
invokes tar, not by tar itself.

There's no POSIX standard for this, but on my Solaris host, I can
raise the number from the default 256 with a shell command like
"ulimit -n 1024".  Perhaps that will work for you on NT as well.

However, I suspect that, whatever limit you set, tar will overwhelm it
eventually, due to a bug either in tar proper, or in the NT port, or
perhaps in ClearCase itself.  If I'm right, you'll have to find out
what that bug is.

I do know of one ClearCase bug that does affect tar, though I don't
offhand see why it would cause file descriptor exhaustion.  Here's the
bug.  POSIX.1 requires that two files are identical if st_ino and
st_dev are the same, but ClearCase MVFS incorrectly assigns the same
(device, inode) pair to two distinct files in some cases, and this can
cause problems with tar.  A long time ago someone with ClearCase
support told me that this was ug id ATRia04618; I don't know whether
the bug has since been fixed.  If you have ClearCase support perhaps
you can ask them about it.  Also, ClearCase may know of others who are
in your pickle.

You wouldn't by any chance be using long file names with ClearCase
magic characters in them, would you?  I've never used ClearCase, but I
understand that they can cause problems in this area.