One more thing, when using more than one path (basically anyu san setup) the device mappings will wrap around for every path, so for two paths... single hba, dual controller.. three disks will look like this... disk1=/dev/sda disk2=/dev/sdb disk3=/dev/sdc disk1=/dev/sdd disk2=/dev/sde disk3=/dev/sde and four like this.. disk1=/dev/sda disk2=/dev/sdb disk3=/dev/sdc disk4=/dev/sdd disk1=/dev/sde disk2=/dev/sde disk3=/dev/sdf disk4=/dev/sdg Or for dual hba, dual controller (4 paths) disk1=/dev/sda disk2=/dev/sdb disk3=/dev/sdc disk4=/dev/sdd disk1=/dev/sde disk2=/dev/sde disk3=/dev/sdf disk4=/dev/sdg disk1=/dev/sdh disk2=/dev/sdi disk3=/dev/sdj disk4=/dev/sdk disk1=/dev/sdl disk2=/dev/sdm disk3=/dev/sdn disk4=/dev/sdo etc... Cheers With the Qlogic drivers in failover mode, you'll get this.. disk1=/dev/sda disk2=/dev/sdb disk3=/dev/sdc disk4=/dev/sdd even though there are multiple paths Corey -----Original Message----- From: linux-cluster-bounces@xxxxxxxxxx [mailto:linux-cluster-bounces@xxxxxxxxxx] On Behalf Of Kovacs, Corey J. Sent: Tuesday, September 26, 2006 7:38 AM To: isplist@xxxxxxxxxxxx; linux clustering Subject: RE: General FC Question You don't say which FC cards you are using but if it's qlogic, then the driver can be set to combine the devices. Basically whats happened is that your machine is picking up the alternate path to the device, which is a perfectly valid thing to do, it's just not what you need at this point. It may be as simple as your secondary controller actually has the lun you are trying to access. To work around yo might just be able to reset the seconday controller and force the primary to take over the LUN. This happens quite a bit depending on your setup. The Qlogic drivers, when setup for failover, will coelesce the devices into a single device by the WWID of the LUN. If that's not an option, then try the multipath tools support in RHEL4.2 or above. You won't be using the /dev/sd{a,b,c,...} devices, rather it'll be /dev/mpath/mpath0 etc, or whatever you set them to instead. Even without failover, the latest Qlogic drivers will make both paths active so that you never end up with a dead path upon boot up. Hope this helps. Corey -----Original Message----- From: linux-cluster-bounces@xxxxxxxxxx [mailto:linux-cluster-bounces@xxxxxxxxxx] On Behalf Of isplist@xxxxxxxxxxxx Sent: Monday, September 25, 2006 11:18 AM To: linux-cluster Subject: General FC Question After adding storage, my cluster comes up with different /dev/sda, /dev/sdb, etc settings. My initial device now comes up as sdc when it used to be sda. Is there some way of allowing GFS to see the storage in some way that it can know which device is which when I add a new one or remove one, etc? Hard loop ID's on the FC side I think but is there anything on the GFS side? Mike -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
