From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Mon, 18 Sep 2006 16:24:41 -0700 (PDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.168.29]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id k8INOVZd007935 for ; Mon, 18 Sep 2006 16:24:35 -0700 Received: from ext.agami.com (64.221.212.177.ptr.us.xo.net [64.221.212.177]) by cuda.sgi.com (Spam Firewall) with ESMTP id 04462D17674E for ; Mon, 18 Sep 2006 15:14:22 -0700 (PDT) Received: from agami.com ([192.168.168.132]) by ext.agami.com (8.12.5/8.12.5) with ESMTP id k8IME52c012758 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Mon, 18 Sep 2006 15:14:05 -0700 Received: from mx1.agami.com (mx1.agami.com [10.123.10.30]) by agami.com (8.12.11/8.12.11) with ESMTP id k8IME04g021516 for ; Mon, 18 Sep 2006 15:14:00 -0700 Message-ID: <450F1A1F.1020204@agami.com> Date: Tue, 19 Sep 2006 03:43:51 +0530 From: Shailendra Tripathi MIME-Version: 1.0 Subject: Re: swidth with mdadm and RAID6 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: cousins@umit.maine.edu Cc: "\"xfs@oss.sgi.com\" " Hi Steve, Your guess appears to be correct. md_ioctl returns nr which is total number of disk in the array including the spare disks. However, XFS function md_get_vol_stripe does not take spare disk into account. It needs to subtract spare_disks as well. However, md.spare_disks returned by the call returns spare + parity (both). So, one way could be substract spare_disks directly. Otherwise, the xfs should rely on md.raid_disks. This does not include spare_disks and nr.disks should be changed for that. When I run my program md_info on raid5 array with 5 devices and 2 spares, I get [root@ga09 root]# ./a.out /dev/md11 Level 5, disks=7 spare_disks=3 raid_disks=5 Steve can you please compile the pasted program and run on your system with md prepared. It takes /dev/md as input. In your case, you should get above line as: Level 6, disks=11 spare disks=3 raid_disks=10 nr=working=active=failed=spare=0; ITERATE_RDEV(mddev,rdev,tmp) { nr++; if (rdev->faulty) failed++; else { working++; if (rdev->in_sync) active++; else spare++; } } info.level = mddev->level; info.size = mddev->size; info.nr_disks = nr; .... info.active_disks = active; info.working_disks = working; info.failed_disks = failed; info.spare_disks = spare; -shailendra The program is pasted below: md_info.c. Takes /dev/md as name. For example, /dev/md11. #include #include #include #ifndef MD_MAJOR #define MD_MAJOR 9 #endif #define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, struct md_array_info) struct md_array_info { __uint32_t major_version; __uint32_t minor_version; __uint32_t patch_version; __uint32_t ctime; __uint32_t level; __uint32_t size; __uint32_t nr_disks; __uint32_t raid_disks; __uint32_t md_minor; __uint32_t not_persistent; /* * Generic state information */ __uint32_t utime; /* 0 Superblock update time */ __uint32_t state; /* 1 State bits (clean, ...) */ __uint32_t active_disks; /* 2 Number of currently active disks */ __uint32_t working_disks; /* 3 Number of working disks */ __uint32_t failed_disks; /* 4 Number of failed disks */ __uint32_t spare_disks; /* 5 Number of spare disks */ /* * Personality information */ __uint32_t layout; /* 0 the array's physical layout */ __uint32_t chunk_size; /* 1 chunk size in bytes */ }; int main(int argc, char *argv[]) { struct md_array_info md; int fd; /* Open device */ fd = open(argv[1], O_RDONLY); if (fd == -1) { printf("Could not open %s\n", argv[1]); exit(1); } if (ioctl(fd, GET_ARRAY_INFO, &md)) { printf("Error getting MD array info from %s\n", argv[1]); exit(1); } close(fd); printf("Level %d, disks=%d spare_disks=%d raid_disks=%d\n", md.level, md.nr_disks, md.spare_disks, md.raid_disks); return 0; }