EMC | Changing Failover Mode while array is in use

R

RiDDLeRThC

2[H]4U
2FA
Joined
Jun 13, 2002
Messages
3,963
This may be a stupid question but I'm extremely cautious when it comes to our array in production.

I need to change the Failover Mode from 1 to 4 and also need to adjust the Path Selection from MRU to RR.

Is this okay to do while data is flowing, should I do this during a maint. window?
 
Enabling ALUA, eh? I'd do it during a maintenance window as you want to move everyone at the same time else you may start having LUN thrashing.
 
NetJunkie said:
Enabling ALUA, eh? I'd do it during a maintenance window as you want to move everyone at the same time else you may start having LUN thrashing.
Click to expand...

Think we will experience any downtime? I have a maint. window this evening so I will do it then.

Right now I have one server running with ALUA enabled. 4 right now do not. I forgot to do it when I put the servers in :(.
 
Do NOT do that with it up. Trust me on this.

DO NOT.

Protip 2 for the week: If you have a clariion, and are using ALUA mode, have a real Lun 0.
 
Yeah I did not do this on Friday night. I started to and then saw the warning message being thrown from the Clariion about host disconnect.

I did change the path selection from MRU to RR.

I will take each host down one by one to change it to ALUA.
 
Lopoetve -

what did you mean by "If you have a clariion, and are using ALUA mode, have a real Lun 0."
 
The CLARiiON throws a fake LUN 0 out there even if a host is not zoned to any storage. It's also known as LUN Z. It's a simple way to make sure the host sees the array (fabric is zoned correctly) and allows for some host configuration communication. I haven't heard the reasoning for making a real LUN 0 with ALUA so I'm interested in that too.
 
Yeah I noticed that the fake LUN goes away once you register the host to a storage group.
 
NetJunkie said:
The CLARiiON throws a fake LUN 0 out there even if a host is not zoned to any storage. It's also known as LUN Z. It's a simple way to make sure the host sees the array (fabric is zoned correctly) and allows for some host configuration communication. I haven't heard the reasoning for making a real LUN 0 with ALUA so I'm interested in that too.
Click to expand...

Known issue, has to do with Navireg registrations. You want a real LUN 0. :)
 
To any host in the storage group.

Basically, you need a LUN with HLU (host lun identifier) 0. Array ID doesn't matter. That make sense?
 
You must log in or register to reply here.
Back
Top