how are these systems connected right now ? Direct connect or through a switch ?

yep, as soon as you enable Access Logix ..it will disable access to the system that are currently connected. I would plan for downtime ..bring systems down, enable access logix, create storage groups, populate storage groups with appropriate LUNs, Host(s) and bring systems back online.

A dedicated Clariion for 1 cluster ! Cool.
I've always enabled AL. Always. AFAIK there's no advantage by not doing so.

And that's why you probably want to enable it now

you have to have AL disabled if you are using Veritas Storage foundation running on Cisco SSM module. I dedicated the whole FC4700 for that proof of concept

It's currently connected through a switch. There are two other servers using storage on it and I need to put another one.

Do you think it's possible in my current config to reconfigure without having to restore from tape at all?

You shouldn't actually lose any data doing this, but I'm not certain if this will change how the host recognizes the devices (I suspect it does, but hopefully someone can confirm this).

Worst case scenario should be that you have to reconfigure the OS to pick up these devices again properly once they are in a Storage Group with the initiators for your hosts.

This change doesn't force you to destroy the LUNs themselves, so your data should be safe.

You should enable access logix and make use of the software. Without AL - all LUNs are visible to all hosts connected to the array - which is not preferred and may create many issues.

As Dynamox suggested, please plan for the downtime and follow the broad steps he mentioned.

If required, please engage your EMC support person or put a call to EMC CLARiiON Support to get all the guidance and suggestions, if you want.

Thanks,
Sandip

oh yeah ..data will be intact. It's just a matter of planning, which LUNs will need to be presented to which hosts ..etc.

Sorry, I was just looking at my response and realized that I should qualify it somewhat with...

No matter what, you should still make sure you have a good full backup to restore from just in case

You should determine what the two current hosts are configured for - if you do not have AL enabled, then the hosts are probably in a cluster - the only way to keep them from stepping on each other's LUNs.

Once you detemine how the LUNs are used by the existing hosts, you can then plan how you want to connect them in your new configuration with AL enabled. You will probabaly need to disconnect the existing hosts before you enable AL, then create enable AL, create a new Storage Group for the two hosts, add the LUNs into the new SG, connect the hosts, and add them to this SG. That puts all the LUNs and the hosts back into a single SG - similar to what you had before.

As someone else said, the devices that the hosts see may or will change, but the data on the LUNs should be intact - but have a backup ready just in case.

regards,

glen

My setup is not clustered. It's just two servers accessing the SAN without any proper storage groups setup. I imagine corruption of data could happen quite easily if they tried to access each other's drives.

I think it usually would be simple but the past SAN admin spanned an existing drive from the server to the drives on the SAN using windows. In this situation I don't think there would be any way to disconnect the existing drives on the server and only have a storage group on the SAN, would there?

Let me know if I'm wrong but the only option I see would be to delete the drive in windows, create appropriate the storage group on the SAN, recreate the same drive letter on the server to point to the storage group on the SAN, then restore from backup.

or present a new LUN to the server ..copy data from the existing drive to the new LUN and then use it as your data drive when you put it in the storage group. Why would somebody span internal drive and SAN drive ...Ewwww