Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Date: Tue, 1 Feb 2005 09:59:50 -0500 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: Fwd: Re: cp command - problem with sparse Message-ID: <20050201145950.GC4186@trixie.casa.cgf.cx> Reply-To: cygwin AT cygwin DOT com References: <41FF88C8 DOT 5060604 AT byu DOT net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41FF88C8.5060604@byu.net> User-Agent: Mutt/1.4.1i On Tue, Feb 01, 2005 at 06:48:56AM -0700, Eric Blake wrote: >This question came up on the coreutils list: > >Does cygwin provide any support for sparse files on NTFS volumes that >support it? lseek() could be patched to use FSCTL_SET_ZERO_DATA when a >seek jumps past the end of a file open for writing, but there is still the >issue of when that file is given the FSCTL_SET_SPARSE attribute. Yes. % fgrep FSCTL_SET_SPARSE *.cc fhandler.cc: BOOL r = DeviceIoControl (h, FSCTL_SET_SPARSE, NULL, 0, NULL, fhandler.cc: syscall_printf ("%d = DeviceIoControl(%p, FSCTL_SET_SPARSE, " There are limitations on when a file is considered sparse, however. The archives probably have more details. cgf -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/