Re: iSCSI failover and reconfiguration

[csapuntz@cisco.com]

Here's a little proposal I wrote up a while back but never posted:

When the initiator attempts to login to a given Target,
it gets a response:

Redirect: domain.name/modifier

The initiator would attempt to connect to the new domain name and
modifier. The initiator would follow at most 7 redirects.

The redirected name is presented to the machine you connect to in
the Target: field of the login message.

A similar response is Resolve

Resolve: domain.name/modifier

Again, the initator should try to connect to the new machine.
In this case, the original name should be presented to the target.

This mechanism allows you to build primitive name resolution into iSCSI.

-Costa






-Costa

Mike Kazar <kazar@icubed.com> writes:

> In the iSCSI protocol document, a SCSI target is named by a URL, with the 
> assumption being that DNS would map the domain name to a set of IP 
> addresses.   This works fine when the set of servers that might be 
> supporting the SCSI target is fixed for all time.
> 
> In the NFS V4 specification, the protocol allows the migration of a file 
> system from one server to another, by allowing for an error code that 
> directs the initiator to a new location for that file system.
> 
> I believe that this would be a useful feature to have in iSCSI as 
> well.  With the addition of a distinctive error that indicates 
> responsibility for a particular target has been moved to a different URL, 
> migration of a SCSI target between IP hosts could be achieved in iSCSI, 
> just as migration of file system can be performed in NFS V4.
> 
> Do other readers think this would be a good thing to support in iSCSI?
> 
> 	Mike
> 		(kazar@spinnakernet.com)