Hi, I am trying to figure out the best way to implement multipath failover for an Engenio RAID storage system. I am running SuSE 9.3 x86-64 on the host. The multipath-tools-0.2.1-3 is installed. The kernel is 2.6.11.4-21.7-smp. I am currently using the storage sytem without multipath. 6 LUNs plus a special access device are mapped (twice each) to devices /dev/sda - /dev/sdm. The redundant device names represent paths via each of the 2 RAID controlers in the system. Each LUN is formatted with a LVM2 partition, and all 6 are joined to form 1 logical volume, using the currently active devices. The problem, of course is that in the event of a failover of 1 of the controllers, the devices assigned to it become inactive, and IO is routed through the other controller, using the other device names. In that event, it should be possible to reboot the host system, and it should be able to reconstruct the LVM volume group, since LVM2 uses the wwid of the LUNS, instead of the device names. But, that involves interruption of serice and downtime, and defeats the purpose of having a dual controller system. So, I need to get multipath working. and so far, I don't know how to do it. From what I have been able to gather from the multipath-tools homepage http://christophe.varoqui.free.fr it work with the dev-mapper system in 2.6.x, and you typically set it up by defining the device maps at the command prompt wth /sbin/multipath. It is not clear from the documentation what makes the dm table persistent across reboots. It does say that you can optionally use a file /etc/multipath.conf but there is no example of this file provided, and I have no idea what the syntax would be. The documentation does say that you should be able to run the command multipath -v and it should come back with a list of paths, multipaths, and device maps. When I do that, it reports nothing. Could it be that this will only work if you have previously defined device maps? Or is it that my hardware is not recognized by version 0.2.1-3 of multpath-tools? I am hesitant at ths point to start adding device maps at the command prompt, because the system is in service, and I can't afford to take it off line right now (beside, I have no idea what I'm doing). Anyway, I should mention that there is a bug in the /etc/init.d/multipathd init script. The "restart" section is missing, but a simple edit will fix that. After fixing the init script, multipathd can be configured with the runlevel editor and it loads normally. Now, I noticed that SLES9 SP1 includes multipath-tools-0.3.6-0.3. This is a more recent version than is included in SuSE Professional 9.3, and was presumably added to improve functionality. Question: How well does SLES9 handle multipath devices? Maybe the soution to my problem is to buy SLES9? Any help or advice on this issue would be greatly appreciated. Thanks, John Craig __________________________________________________________________ Switch to Netscape Internet Service. As low as $9.95 a month -- Sign up today at http://isp.netscape.com/register Netscape. Just the Net You Need. New! Netscape Toolbar for Internet Explorer Search from anywhere on the Web and block those annoying pop-ups. Download now at http://channels.netscape.com/ns/search/install.jsp