From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christophe Varoqui Subject: Re: multipath and StorageWorks HSG80 Date: Thu, 20 Apr 2006 22:07:50 +0200 Message-ID: <4447EA16.9070708@free.fr> References: <20060420194321.GE29759@ingress.sbb.uvm.edu> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20060420194321.GE29759@ingress.sbb.uvm.edu> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids Steve Feehan a =E9crit : > Hello. I'm trying to figure out multipath on a StorageWorks HSG80 > contoller. I'm using Ubuntu "Dapper" with the following software > versions: > > kernel: 2.6.15-20-server > multipath-tools: 0.4.7-1ubuntu4 > > >From what I've been reading[1], I gather that I need to use the > dm-hp-sw kernel module. So I applied the patches[2,3,4,5] to > the kernel and setup the /etc/multipath.conf as follows: > > devices { > > device { > vendor "DEC" > product "HSG80" > path_grouping_policy group_by_serial > path_checker hp_sw > features "1 queue_if_no_path" > hardware_handler "1 hp_sw" > } > } > > multipaths { > multipath { > wwid 60001fe10015bf500009947159810015 > alias red > } > } > > >From what I can tell, it is basically working: > > sfeehan@dogwood:~$ sudo multipath -ll > red (360001fe10015bf500009947159810015) > [size=3D203 GB][features=3D1 queue_if_no_path][hwhandler=3D1 hp_sw] > \_ round-robin 0 [prio=3D2][active] > \_ 0:0:0:1 sda 8:0 [active][ready] > \_ 0:0:1:1 sdb 8:16 [active][ready] > \_ round-robin 0 [prio=3D2][enabled] > \_ 0:0:2:1 sdc 8:32 [active][ghost] > \_ 0:0:3:1 sdd 8:48 [active][ghost] > > > And now the problem: I see quite a few errors in dmesg: > > > [42949392.230000] sd 0:0:2:1: Device not ready. > [42949392.230000] end_request: I/O error, dev sdc, sector 426583424 > [42949392.230000] printk: 515 messages suppressed. > [42949392.230000] Buffer I/O error on device sdc, logical block > 213291712 > [42949392.230000] sd 0:0:2:1: Device not ready. > [42949392.230000] end_request: I/O error, dev sdc, sector 426583424 > [42949392.230000] sd 0:0:3:1: Device not ready. > [42949392.230000] end_request: I/O error, dev sdd, sector 426583424 > [42949392.230000] sd 0:0:3:1: Device not ready. > [42949392.230000] end_request: I/O error, dev sdd, sector 426583424 > > > And when I put LVM on top of the multipath device I get lots > of errors: > > sfeehan@dogwood:~$ sudo pvcreate /dev/mapper/red > Physical volume "/dev/mapper/red" successfully created > sfeehan@dogwood:~$ sudo vgcreate vg0 /dev/mapper/red > Found duplicate PV qDhK4gPTGtzXAm7jPQf0uf07a0FQs2qL: using /dev/sdb1 > not /dev/sda1 > /dev/sdc: read failed after 0 of 2048 at 0: Input/output error > /dev/sdd: read failed after 0 of 2048 at 0: Input/output error > Found duplicate PV qDhK4gPTGtzXAm7jPQf0uf07a0FQs2qL: using /dev/sda1 > not /dev/sdb1 > Found duplicate PV qDhK4gPTGtzXAm7jPQf0uf07a0FQs2qL: using /dev/sdb1 > not /dev/sda1 > /dev/sdc: read failed after 0 of 1024 at 0: Input/output error > /dev/sdc: read failed after 0 of 2048 at 0: Input/output error > /dev/sdd: read failed after 0 of 1024 at 0: Input/output error > /dev/sdd: read failed after 0 of 2048 at 0: Input/output error > Volume group "vg0" successfully created > sfeehan@dogwood:~$ > sfeehan@dogwood:~$ > sfeehan@dogwood:~$ sudo lvcreate -L 10G -n test vg0 > Found duplicate PV qDhK4gPTGtzXAm7jPQf0uf07a0FQs2qL: using /dev/sdb1 > not /dev/sda1 > /dev/sdc: read failed after 0 of 2048 at 0: Input/output error > /dev/sdd: read failed after 0 of 2048 at 0: Input/output error > Logical volume "test" created > sfeehan@dogwood:~$ > > > So... what are the errors about? Are they significant? What > if anything can I do to resolve them? > > Thanks. > > Steve > > > [1] [dm-devel] StorageWorks multipath support > http://www.redhat.com/archives/dm-devel/2005-June/msg00105.html > > [2] [dm-devel] [PATCH RFT/RFC 1/4] export block layer helpers > http://www.redhat.com/archives/dm-devel/2005-September/msg00097.htm= l > > [3] [dm-devel] [PATCH RFT/RFC 2/4] add dm_scsi helpers > http://www.redhat.com/archives/dm-devel/2005-September/msg00098.htm= l > > [4] [dm-devel] [PATCH RFT/RFC 3/4] convert dm emc > http://www.redhat.com/archives/dm-devel/2005-September/msg00099.htm= l > > [5] [dm-devel] [PATCH RFT/RFC 4/4] add dm-hp-sw hw handler > http://www.redhat.com/archives/dm-devel/2005-September/msg00100.htm= l > > =20 Overall, that's very good howto material, if you care to feed the wiki. The IO errors are due to lvm tools trying to scan the individual paths,=20 including those not usable, where they should only care about the=20 multipath devices. You should blacklist the individual path in the lvm config. Regards, cvaroqui