Date: Fri, 4 Dec 1998 15:07:07 GMT From: "Stephen C. Tweedie" <sct@redhat.com> To: Tigran Aivazian <tigran@aivazian.demon.co.uk> Subject: SAR (was Re: disks stats through /proc) Hi, On Thu, 3 Dec 1998 13:39:42 +0000 (GMT), Tigran Aivazian <tigran@aivazian.demon.co.uk> said: > IMHO, this should be done on a fine-grained (partition level) rather than > coarse (drive) level. There is enough information in > ll_rw_blk.c/add_request() to do it now but, of course, kernel_stat > structure will have to be seriously modified. > There is something frustrating about the quality and speed of Linux > development. I.e. the quality is too high and the speed is too high, > in other words, I can implement this disk stat feature, but I bet > someone else has already done it and is just about to release his > patch to Linus soon... Yep, done that. :) I have patches for 2.0.34/35 and 2.1.125 already working, outputing both per-partition and per-spindle access stats via /proc/partitions. A "sard" front-end gives human-readable output. (It is modeled on the output of the SVR4 "sar -d" output.) Currently you get average %utilisation; average request queue length; number of K transfered plus number of distinct IOs for reads, writes and combined; and average request service time for each disk and each partition. Look for ftp://ftp.uk.linux.org:/pub/linux/sct/fs/sard-0.2.tar.gz for the patches and sard source code. The plan is to integrate this into 2.3 once we have got a more sensible kdev_t in the kernel. --Stephen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/