iinfi
7th June 2009, 21:47
i am a novice Linux admin and our office does not have a storage box. i am using openfiler as a storage to practice different stuff which need common storage.
i am practicing clustering with RHEL5.3 and facing an issue with mapping common storage with the RHEL 5.3 nodes.
i tried to create a 2 node cluster and here is what i am facing.
i created 3 LUNs on my openfiler and ran the following commands on both nodes.
iscsiadm --mode discovery --type sendtargets --portal 192.168.1.10
when i ran fdisk -l on each node i find that the LUNs are mapped but they are not in correct sequence
on node 1 -- LUN1 -- /dev/sdb
on node 1 -- LUN2 -- /dev/sdc
on node 1 -- LUN3 -- /dev/sdd
but on node 2
on node 2 -- LUN1 -- /dev/sdb
on node 2 -- LUN3 -- /dev/sdc
on node 2 -- LUN2 -- /dev/sdd
/dev/sdc and /dev/sdd are swapped. i am not too sure whether things would work right when i configure any application on the cluster.
is there a way to map a LUN to a specific drive? like map LUN 1 to /dev/sdb and LUN2 to /dev/sdc and so on so that consistency can be maintained on all nodes.
there is a procedure given here (http://www.idevelopment.info/data/Unix/Linux/LINUX_ConnectingToAniSCSITargetWithOpen-iSCSIInitiatorUsingLinux.shtml) but i am not able to follow it correctly and it doesnt seem to work. is there any other way around for the same? mapping drives through UUID is an option which someone suggested here (http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1342328) but if i need raw devices this might not work.
i am novice linux fellow so please excuse if the above query looks too stupid.
i am practicing clustering with RHEL5.3 and facing an issue with mapping common storage with the RHEL 5.3 nodes.
i tried to create a 2 node cluster and here is what i am facing.
i created 3 LUNs on my openfiler and ran the following commands on both nodes.
iscsiadm --mode discovery --type sendtargets --portal 192.168.1.10
when i ran fdisk -l on each node i find that the LUNs are mapped but they are not in correct sequence
on node 1 -- LUN1 -- /dev/sdb
on node 1 -- LUN2 -- /dev/sdc
on node 1 -- LUN3 -- /dev/sdd
but on node 2
on node 2 -- LUN1 -- /dev/sdb
on node 2 -- LUN3 -- /dev/sdc
on node 2 -- LUN2 -- /dev/sdd
/dev/sdc and /dev/sdd are swapped. i am not too sure whether things would work right when i configure any application on the cluster.
is there a way to map a LUN to a specific drive? like map LUN 1 to /dev/sdb and LUN2 to /dev/sdc and so on so that consistency can be maintained on all nodes.
there is a procedure given here (http://www.idevelopment.info/data/Unix/Linux/LINUX_ConnectingToAniSCSITargetWithOpen-iSCSIInitiatorUsingLinux.shtml) but i am not able to follow it correctly and it doesnt seem to work. is there any other way around for the same? mapping drives through UUID is an option which someone suggested here (http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1342328) but if i need raw devices this might not work.
i am novice linux fellow so please excuse if the above query looks too stupid.