Sharing LUN between hosts

i think you need to look at some kind of clustering solution ...MS Clustering or Veritas. If i understand correctly, you want hosts1 luns to failover to host2 in case host1 fails ? If your os is Windows ..it has to be running windows 2000 Advanced server/2003 Enterprise edition to use MS Clustering.

the right solution is a cluster.. but if you want to manage yourslf w/o cluster you take the risk of monitoring the the LUNS on the servers.. i mean at any time the LUNs should not be activated at both side which could risk the data integrity and a potential data lose.

You could try it manually: mask the luns to 1 host and if that one host fails, mask them to another host and start up your application on that host.

A cluster would be better.

to Clariion only folks you are speaking foreigner language man ..what the heck is masking ?

Ooops... Masking is the act of putting a host in a storage group, so it can see the lun that are in there

i sense a little dutch accent in there ...but overall is a good explanation

ar you looking for "presenting" the LUNS than "masking"?

Hi,

Like anyone is advising USE a kind of CLUSTERING SW.
Otherwise your data can get corrupted.... Even if you are taking good care....

You wrote:


I read: "I want to loose data. Is it the best way??"

Sharing luns between hosts without something managing the access leads usually to data corruption.
Dynamox, Rob and Santhosh gave you good advices .. But please DON'T DO THAT.

My suggestion if you absolutely have to do "poor man's" clustering is to leave each host in its own storage group with its "primary" LUNs.

In the event of a hardware failure move the LUNs from the failed node's storage group to the "active" node's storage group and then run whatever host specific commands you need to run to add the devices and get the application running. This will remove any risk of data corruption.

If you are running Windows I would strongly recommend not sharing LUNs as it can be tricky to avoid having both servers attempt to own/import these devices. There is an option to disable automatic scan/mount (mountvol /N) but once again use at your own risk.

For UNIX variants (AIX/HP) this is a good bit safer, but still presents good opportunity for human error to occur if you are not VERY careful.

Good luck and take care - you could cause yourself a lot of trouble if you miss some steps.

That's exactly what I meant