From mboxrd@z Thu Jan 1 00:00:00 1970 From: Erez Zilber Subject: Re: Setting up a multipath device Date: Sun, 07 May 2006 17:01:01 +0300 Message-ID: <445DFD9D.4040402@voltaire.com> References: <445A0AE9.20907@voltaire.com> <20060504144915.GA2319@pundit> <445A1D88.7030500@voltaire.com> <1146768927.27764.12.camel@localhost.localdomain> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1146768927.27764.12.camel@localhost.localdomain> 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 Some more questions: 1. I couldn't find the config file. Where is it located? Is there any documentation about it? 2. How can I configure fancy naming for devices (instaed of using something like /dev/mapper/3600c0ff00000000007c1d121c397f503) in the config file? 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. I tried to run the following test: I created a multipath device with 2 physical devices (/dev/sda & /dev/sdb). I started running traffic on the multipath device. All traffic ran through /dev/sda. Then, I disconnected the iSCSI target that was represented by /dev/sda. After some time, the traffic was directed to /dev/sdb. I stopped the traffic, disconnected the iSCSI target that was represented by /dev/sdb and reconnected /dev/sda. Now, if I run `multipath -l`, I see the following output: 3600c0ff00000000007c1d121c397f503 [size=10 GB][features=0][hwhandler=0] \_ round-robin 0 [prio=0][enabled] \_ 0:0:0:0 sda 8:0 [failed][undef] \_ round-robin 0 [prio=0][enabled] \_ 1:0:0:0 sdb 8:16 [failed][faulty] /dev/sdb is dead and I'm ok with it. However, /dev/sda is alive. I was able to run the following command: dd if=/dev/sda of=/dev/null count=100000 However, if I run the following command: dd if=/dev/mapper/3600c0ff00000000007c1d121c397f503 of=/dev/null count=100000 This is what I get: dd: reading `/dev/mapper/3600c0ff00000000007c1d121c397f503': Input/output error 0+0 records in 0+0 records out 0 bytes (0 B) copied, 0.00067 seconds, 0.0 kB/s Can't it recongnize that a device that has failed (/dev/sda) is back to life? Thanks Erez