From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christophe Varoqui Subject: Re: Setting up a multipath device Date: Mon, 08 May 2006 23:33:15 +0200 Message-ID: <1147123995.27764.46.camel@localhost.localdomain> References: <445A0AE9.20907@voltaire.com> <20060504144915.GA2319@pundit> <445A1D88.7030500@voltaire.com> <1146768927.27764.12.camel@localhost.localdomain> <445DFD9D.4040402@voltaire.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <445DFD9D.4040402@voltaire.com> 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 Le dimanche 07 mai 2006 =C3=A0 17:01 +0300, Erez Zilber a =C3=A9crit : > Some more questions: >=20 > 1. I couldn't find the config file. Where is it located? Is there an= y > documentation about it? The config file normal location is /etc/multipath.conf > 2. How can I configure fancy naming for devices (instaed of using > something like /dev/mapper/3600c0ff00000000007c1d121c397f503) in > the config file? Have a look at the templates provided with the upstream package. > 3. How can I config the delay from the time that a device has failed > until the dm moves to the next active device? Again, I understand > that I should use the config file somehow. >=20 Ditto. > I tried to run the following test: I created a multipath device with 2=20 > physical devices (/dev/sda & /dev/sdb). I started running traffic on th= e=20 > multipath device. All traffic ran through /dev/sda. Then, I disconnecte= d=20 > the iSCSI target that was represented by /dev/sda. After some time, the= =20 > traffic was directed to /dev/sdb. I stopped the traffic, disconnected=20 > the iSCSI target that was represented by /dev/sdb and reconnected=20 > /dev/sda. Now, if I run `multipath -l`, I see the following output: >=20 > 3600c0ff00000000007c1d121c397f503 > [size=3D10 GB][features=3D0][hwhandler=3D0] > \_ round-robin 0 [prio=3D0][enabled] > \_ 0:0:0:0 sda 8:0 [failed][undef] > \_ round-robin 0 [prio=3D0][enabled] > \_ 1:0:0:0 sdb 8:16 [failed][faulty] >=20 > /dev/sdb is dead and I'm ok with it. However, /dev/sda is alive. I was=20 > able to run the following command: >=20 > dd if=3D/dev/sda of=3D/dev/null count=3D100000 >=20 > However, if I run the following command: >=20 > dd if=3D/dev/mapper/3600c0ff00000000007c1d121c397f503 of=3D/dev/null=20 > count=3D100000 >=20 > This is what I get: >=20 > dd: reading `/dev/mapper/3600c0ff00000000007c1d121c397f503':=20 > Input/output error > 0+0 records in > 0+0 records out > 0 bytes (0 B) copied, 0.00067 seconds, 0.0 kB/s >=20 > Can't it recongnize that a device that has failed (/dev/sda) is back to= =20 > life? >=20 Is the daemon (multipathd) running ? The daemon takes care of path revalidation. Regards, cvaroqui