From mboxrd@z Thu Jan 1 00:00:00 1970 From: "bmoon" Subject: 4k issue on MD device block size Date: Thu, 15 May 2003 19:31:02 -0700 Sender: linux-raid-owner@vger.kernel.org Message-ID: <009001c31b53$32b36900$6901a8c0@bmoon> References: <3EC3685E.3010202@cc.kuleuven.ac.be> <16067.28056.186816.649850@notabene.cse.unsw.edu.au> <3EC3A1D9.5010201@cc.kuleuven.ac.be> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hello, Please provide me an advice on the following issues; I'd like to use 4k block size for both MD super block I/O and regular file I/O, which will improve the performance. Q1: I noticed that it set the "blksize_size" to 4k for MD SB I/O but it use 1K for the regular file I/O. It usually set the size to 1k at system init by "md-init", then it set to 4k for MD SB I/O later. I could not find the place that set it back to 1k. However, it changes to 1 k???? How? Q2: I modified md.c to use the 4k blksize_size. It works but sometimes it crash. System "BLOCK_SIZE" is still 1k, and my hd device blksize_size=1k, too. I changed ONLY 1024 to 4096 on every occurences on md.c. What am I missing? Thanks in advance, Bo