From owner-freebsd-current Thu Aug 19 11:38: 0 1999 Delivered-To: freebsd-current@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id 6EC5614DFD for ; Thu, 19 Aug 1999 11:37:53 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id LAA57058; Thu, 19 Aug 1999 11:33:43 -0700 (PDT) (envelope-from dillon) Date: Thu, 19 Aug 1999 11:33:43 -0700 (PDT) From: Matthew Dillon Message-Id: <199908191833.LAA57058@apollo.backplane.com> To: Darryl Okahata Cc: freebsd-current@freebsd.org, Amancio Hasty Subject: Re: [re]writable cdrom drive References: <199908191821.LAA08673@mina.sr.hp.com> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG : Another possibility, if you have the RAM, is to use the team(1) :program (it's in the ports) to buffer the data as it goes to the burner. :You basically put it into the pipeline between mkisofs and cdrecord, and :it buffers up to 5MB in memory (default, adjustable). Of course, you've :got to have enough RAM to not go into swap during the operation. It's a :very nice program, and I've been told that, with enough memory :(32-64MB), you can be running X11 and compiling programs while the CD is :burning (this is with a 2X burner, though). : :-- : Darryl Okahata : darrylo@sr.hp.com It should be noted that the 'cdrecord' program implements a FIFO itself, and you can specify the size. The default is 2MB. cdrecord uses a shared memory segment and forks so the process buffering the data is made independant of the buffer draining it. Modern CD writers usually have 1-2MB of buffer internally. The newer Yamahas, for example, have 2MB. So right off the bat we have around 4MB. Still, when you are writing at 600KB/sec it is possible to get behind if the filesystem you are building has lots of small files. Apart from writing the mkisofs output to a file, the easiest solution is to tell cdrecord to burn at a slower rate - e.g. 1x or 2x instead of 4x or 6x. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message