[Info-vax] ES47 2G FC and rx2800 i4 8G FC in same VMS Cluster with Shadowsets on shared storage controller? Is this possible?

[Robert A. Brooks]

On 3/12/2020 8:44 PM, Jon Pinkley wrote:
> We currently have a cluster of two ES47s with 2G FC and an EVA6000 with
> 4G FC and 4G FC switches (StorageWorks 4/32B, HP relabeled Brocade)
> 
> We want to migrate to Itanium rx2800 i4 or i6 servers and a shared FC
> storage controller (perhaps 3PAR 8200?).  HPE said that the 3PAR has 16G
> FC and they were not very optimistic about us being able to use it with
> the ES47's.  They said that FC could go up/down 2 speeds, but others
> have said only 1.

The correct answer is 2; a 16Gb/sec switch will also negotiate down
to 8Gb/sec and 4Gb/sec.  HPE is correct in that a 16 Gb/sec switch
will not work with a 2Gb/sec HBA.

> Does anyone have an ES47 with 2G Emulex LP10000 FC HBA in a VMS Cluster
> with an Itanium server with 8G FC HBAs and some shared storage
> controller?

We definitely have Alphas (ES80's) clustered with i2 and i4 servers, where
the IA64 systems have 8Gb/sec adapters (Qlogic ISP2532).  The Alphas
have Emulex LP10000's.

>  If so what storage controller?  This would be a migration
> config, and we plan to migrate storage from EVA to new storage using VMS
> Volume Shadowing (and VMS Clusters).

EVA's; I'm not sure what model.  We also use HBVS with clustering.

> I also don't know if FibreChannel forces two communicating devices to
> negociated at the same speed, or if it is like a store/forward Ethernet
> switch and negociates each link at the lowest speed.

The lower-speed Alpha's connected to the switch do not cause the IA64's
to operate at 2Gb/sec.  If you log onto the fibre switch, you'll see the
speed at which the HBA negotiated with the switch.

> In other words, we currently have 4G switches, 4G EVA controller, and 2G
> ES47.  Does the FC link between the 4G switch and the 4G EVA operate at
> 4G and the link between the 4G switch and 2G ES47s operate at 2G, and
> the switch does store and forward speed conversion like most ethernet
> switches do?

See above; the array will likely log into the switch at the "native" speed of
its adapter port.

Log a support call with us if you need more detail.

-- 
                  -- Rob