Hi Kerry

Based on your previous email I'm somewhat confused what you're actually trying 
to do. It sounds like you want to have 3 iSCSI servers behind two "gateway" 
type servers. The problem with this is unless you format the iSCSI volumes with 
a cluster filesystem then you can't mount the same block device on the two 
"gateway" servers and there really isn't anything that can be done to make that 
situation work. Since you're mounting the iSCSI volumes onto the Openfiler 
boxes and OF doesn't have any native support of cluster file systems as far as 
I know, there would be patching the kernel at that stage at the very least.

I think the problem is you're thinking of your storage architecture like you 
would think of a web farm. What it sounds like you want to do is protect 
against one of the gateway servers failing but that doesn't protect against one 
of the rear iSCSI servers from failing (perhaps you were planning to run 
software raid over the iSCSI volumes, not sure how that would work but it 
should be possible although it still doesn't remove the cluster filesystem 
requirement). I think the best you could do would be to setup multiple HA 
configurations so for each active OF box you have a secondary in passive mode. 
If the active fails then the passive takes over the IP address etc and 
everything continues to work, weather these boxes are straight NAS or iSCSI 
mounted on the windows servers it shouldn't matter. Since you've got an odd 
number of boxes this obviously won't be a perfect solution but I think it's the 
best you could do.

One other possibility that _may_ work is to have the passive gateway mount the 
iSCSI volume read-only and if it loses the heartbeat from the active node then 
remount it RW and have it takeover the IP etc. Doing this, and even doing what 
I think you were suggesting in your previous email, you wouldn't actually need 
any replication at all as you're using the same storage devices, it's 
effectively a SAN and a shared storage pool, all you would need is the 
heartbeat setup properly. The risk here is if the failover doesn't happen fast 
and clean and there are still connected clients to the gateway that's just 
"failed" that write to the storage you'll likely hose the filesystem.

Anyway, more info is required before knowing exactly how you could make it work

Dave

From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kerry L. Kriegel
Sent: Tuesday, 19 February 2008 6:56 a.m.
To: [email protected]
Subject: [OF-users] 2.3 HA question

OpenFilers ----


I understand that the OF 2.2 HA was a single "active" node with replication to 
the "standby" node.
I have installed OF 2.3 and am about to implement HA using the instructions for 
2.2 (the only ones I can find).

My question is.....Is OF 2.3 HA capable of performing with BOTH nodes as 
"active" for load balancing and fault tolerance?
If so, are there any instructions out there for OF 2.3 HA?



Thank you,

Kerry L. Kriegel


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