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 From: "Markus Mauhart" To: cygwin AT cygwin DOT com Date: Thu, 13 Mar 2003 16:09:54 +0100 MIME-Version: 1.0 Subject: cygwin-1.3.21-1, problem with sparse file creation as default Message-ID: <3E70AD52.744.D4BC055@localhost> Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Content-description: Mail message body I have a problem with the following new feature of cygwin-1.3.21-1 > - Create sparse files by default, when possible. (Vaclav Haisman) Couldnt it be made configurable, or removed ? 1) good old file manager (winfile.exe from NT4 system) does not display sparse files - so all newly created files (through gcc, or make, or "cp con 123.txt") are now invisible. (beside browsing, I didnt test real file operations like move/copy a folder containing some sparse files) 2) AFAICS its advantages are very sparse ;-) Only when extending a file's size the sytem (ntfs5+) automatically adds 'sparse' clusters. Otherwise (even when writing 10G of all zero) not a single sector is spared. Only programs aware of win32-sparse files profit from this existing file-attribute when explicitely marking a range as zero, but IMHO this is a micro-profit: such program can replace the following code .... if (make_file_sparse(..)) mark_some_range_as_zero(..); ... with ... if (is_file_sparse(..)) mark_some_range_as_zero(..); Note, this was assuming the win32 file API. Are there any cygwin/GNU file API's (except for file creation;-) which when used then automatically profit from sparse files ? 3) OTOH my guess is that it introduces more or less unnecessary resource consumption (CPU and/or disk) ... one benchmark could be building gcc and messuring time and disk consumption, but last time I built gcc was in 2001; maybe Vaclav Haisman could benchmark the pros and cons of this new feature. (also defragmenting a volume with 10.000 of such newly created 'pseudo-sparse' files might pay a price) Anyway, thanks for your attention, Markus. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/