From owner-freebsd-arch Sat Nov 24 10:49:30 2001 Delivered-To: freebsd-arch@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 28C9637B419 for ; Sat, 24 Nov 2001 10:45:28 -0800 (PST) Received: (from dillon@localhost) by apollo.backplane.com (8.11.6/8.9.1) id fAOIjM377587; Sat, 24 Nov 2001 10:45:22 -0800 (PST) (envelope-from dillon) Date: Sat, 24 Nov 2001 10:45:22 -0800 (PST) From: Matthew Dillon Message-Id: <200111241845.fAOIjM377587@apollo.backplane.com> To: Kirk McKusick Cc: Sheldon Hearn , freebsd-arch@FreeBSD.ORG Subject: Re: Using a larger block size on large filesystems References: <200111240936.fAO9aXH03886@beastie.mckusick.com> Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG :I am of the opinion that we should default to 16K/2K for most :filesystems today. I believe that the change should be in newfs. : : Kirk McKusick The only thing I worry about is reduced performance when doing random database accesses, which makes me kinda want to give the system the capability to do smaller I/O's :-) But apart from that worry I agree completely. We get fewer indirection levels (64MB multiplier instead of 16MB per indirection block) , smaller bitmaps (1/2 the size), and less strain on the clustering code (at least for sequential I/O). Memory is getting cheap and filesystems are getting larger, too. Sheldon, I think you have a go to change the newfs default. Do it! p.s. side note on the buffer cache: The buffer cache is optimized for both 1K/8K and 2K/16K, but it is *NOT* optimized for anything larger. 2K/16K is thus the largest configuration we can use optimally in regards to the buffer cache. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message