Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 22 Jun 2002 13:41:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 22 Jun 2002 13:41:32 -0400 Received: from swm.pp.se ([195.54.133.5]:5068 "EHLO uplift.swm.pp.se") by vger.kernel.org with ESMTP id ; Sat, 22 Jun 2002 13:41:32 -0400 Date: Sat, 22 Jun 2002 19:41:26 +0200 (CEST) From: Mikael Abrahamsson To: linux-kernel@vger.kernel.org Subject: max buffering per disk? Message-ID: Organization: People's Front Against WWW MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2336 Lines: 53 Running the redhat 7.3 supplied 2.4.18-5smp kernel, and before that the redhat 7.2 supplied 2.4.9-31 kernel, I notice that I now get worse interactive performance when the machine is doing a lot of disk io. Using iostat/vmstat I see that there is not a lot of activity going on on the system drive, but rather on the drives containing a lot of files which are accessed/downloaded (web and ftp file serving). I interpret this as that the files being service are being cached and the caching of the mostly used files (on the system drive) is being thrown out. Most of these files on the file-drives are only sent once and therefore there is no use in caching them. Is there some way of setting that the kernel can only use so much memory to cache a specific drives content, or that a certain drive gets at least X amount of megs to cache its contents? I have over 1 gig of memory and user processes usually don't use that much memory: total used free shared buffers cached Mem: 1160264 1150424 9840 0 66820 964292 -/+ buffers/cache: 119312 1040952 Swap: 4427928 30680 4397248 I would therefore like the system drive to always use say 128M or 256M for buffering it's contents, or as an alternative, say that my file drives cannot use more than 256M altogether for caching. Is there a knob to do this, if not, is it anything that might be implemented in the future? I have read the tuning page and changed my bdflush settings accordingly but that didn't do much difference as far as I can see. Btw, file serving performance is no problem, that works great, I can transfer 15-20Megabyte/s using my Netgear 622T card. The 2.4.9 kernel seemed to have a better interactive performance on the same load at the price of raw performance. I got slightly better fileserving performance after upgrading to 2.4.18, but the interactive performance is much worse. Any help appreciated. -- Mikael Abrahamsson email: swmike@swm.pp.se - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/