From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n2JILXbG010462 for ; Thu, 19 Mar 2009 14:21:33 -0400 Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id n2JILDal010146 for ; Thu, 19 Mar 2009 14:21:13 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e36.co.us.ibm.com (8.13.1/8.13.1) with ESMTP id n2JIJrFo025155 for ; Thu, 19 Mar 2009 12:19:53 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n2JILB25087802 for ; Thu, 19 Mar 2009 12:21:12 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n2JILBAP006595 for ; Thu, 19 Mar 2009 12:21:11 -0600 Received: from [9.47.17.98] (chandra-ubuntu.beaverton.ibm.com [9.47.17.98]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id n2JILAxX006512 for ; Thu, 19 Mar 2009 12:21:11 -0600 Subject: Re: [linux-lvm] multipath question From: Chandra Seetharaman In-Reply-To: <49C29649.7040402@sivell.com> References: <49C29649.7040402@sivell.com> Date: Thu, 19 Mar 2009 11:24:13 -0700 Message-Id: <1237487053.26341.12.camel@chandra-ubuntu> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Reply-To: sekharan@linux.vnet.ibm.com, LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development On Thu, 2009-03-19 at 13:00 -0600, vu pham wrote: > I set up multipath on /dev/sda and /dev/sdb which are mapped from a > remote single disk, which has two partitions. > > Below are some output. > [root@vm5 mpath]# ls -l > total 0 > lrwxrwxrwx 1 root root 7 Mar 19 10:34 mpath0 -> ../dm-2 > lrwxrwxrwx 1 root root 7 Mar 19 10:34 mpath0p1 -> ../dm-3 > lrwxrwxrwx 1 root root 7 Mar 19 10:34 mpath0p2 -> ../dm-4 > > [root@vm5 mpath]# multipath -ll > mpath0 (16465616462656166313a3100000000000000000000000000) dm-2 > IET,VIRTUAL-DISK > [size=5.0G][features=0][hwhandler=0] > \_ round-robin 0 [prio=0][active] > \_ 0:0:0:1 sda 8:0 [active][ready] > \_ round-robin 0 [prio=0][enabled] > \_ 1:0:0:1 sdb 8:16 [active][ready] > [root@vm5 mpath]# > > > From the multipath command, I know dm-2 is mapped from two devices > /dev/sda and /dev/sdb as expected. > > But how can I know if dm-3 is mapped from /dev/sda1 and /dev/sdb1, and > dm-4 from /dev/sda2 and /dev/sdb2 ? > > The command "multipath -ll" only gives info on mpath0 or dm-2. > > I tried multipath -ll /dev/mpath/mpath0p1 but does not show anything. mpath0 is analogous to sda and mpath0p1, mpath0p2 are analogous to sda1, sda2. since there is "mpath0" in mpath0p1 and mpath0p2, you can be sure that they are built off sda and sdb (in effect mpath0p1 is made of sda1 and sdb1 and so on)... > > Thanks, > > Vu > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/