shared storage not updating on all nodes

Question

Hi,

I hope this is an easy on since I am new to EMC.

I have three Linux nodes each has the naviagentcli installed and the agent.config file is below. I have created a storage group and assigned a LUN and the three nodes to the storage group. Each node can mount the presented LUN. The problem is that each node operates as if in a vacuum. If node A copies or removes a file, none of the other nodes will see that unless I remount the volume.

Not sure what the problem is and I can not seem to find the right doc that talks about this. If you could please point me to the right doc or tell me what I am doing wrong, I would appreciate it.

Thanks,

###########################
# Navisphere agent.config
###########################

clarDescr Navisphere Agent
clarContact
device auto auto
#user root # only on this machine
user root@lcm1ddb04
user root@lcm1ddb05
user root@lcm1ddb06

poll 60
eventlog 100
baud 9600

Allen Ward · Answer

It isn't clear from your post, but I'm assuming from the fact that you didn't mention it that your Linux hosts are not running in a cluster configuration.

With a CLARiiON, you should not have multiple hosts connected to the same LUN unless they are running Cluster software... or some other method of arbitrating file system access (e.g. multiple VM ESX servers).

Outside of those special situations, you should always maintain a 1-to-1 mapping of hosts to Storage Groups.

If you ARE running a cluster, you may have to check the configuration of your cluster to determine the problem.

If my first guess was correct, maybe if you explain in more detail what you are trying to achieve, we can come up with another solution that will meet your needs.

ruroruro · Answer

If you do not have cluster, that config does not work.

All 3 server cannot see all LUNs that you attached.

If you wanna use those LUNs, you should make 1 storage group per server.

That means if server A has LUN A, other B, C servers cannot see LUN A.

boogie1 · Answer

okay, so that make more sense, currently I do not have any cluster service running but do what to build an Oracle RAC cluster. I will have a look at ASM and OCFS2 now. I was thinking that the EMC did more than it does.

Thanks,

csmykay1 · Answer

I hate people that still use this 'theory.' Here is a good rule of thumb with SG assignment's (latest FLARE) on a CX in regards to the OS view.Linux:You can add multiple nodes to the same SG (No Problem), but do not 'need' clustering software.All nodes can 'see' the disk just fine. However you can not (nor should you even try, trust me I have ) write to the same LUN from multiple host's. The main reason's for these have to do with the filesystem. If you are looking for a system like this then I recommend a RedHat GFS cluster.Windows:You can add multiple nodes to the same SG (No Problem), but you DO 'need' clustering software.The way that the Windows disk sub-system handles a disk at the SCSI layer will cause all nodes to 'Fight' over the disks.I just wanted to clarify what you can actually do from a Storage Group perspective.Regards,Shmac

USShivas · Answer

Hey, Are you using nis on Linux ? If you are using nis update the nis map and push the map. So that you can see the luns on every host.Hope this will be useful. Thanks & Regards, USshivas

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shared storage not updating on all nodes

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