MSA 1000 maximum hosts

[Mark_459]

Hi,

Just wondering what the maximum hosts you can have connected to MSA1000 with dual controllers and 2 8 port switches.

I was under the impression that because the controllers can only run in an active/passive configuration that you could only have 7 hosts connected (either single or multi pathed) but have been advised otherwise i.e 14 hosts.

Many thanks,

[Uwe Zessin]

Mark,
the theoretical number is 32 hosts, because a MSA1000 can present up to 32 logical disks. The supported number depends on the operating system (e.g. tested number of cluster members, etc.) and you connectivity.

You have an MSA1000 with dual controllers and one 8-port switch per controller - that leaves you with 7 ports for the hosts, correct.

Under certain circumstances you can connect a single-pathed host, but it *must* go to the active controller. So your impression is, again, correct: you can only operate 7 hosts in this configuration.

[Stephen Kebbell]

Hi,

according to the latest compatibility matrix, the MSA1000 can support up to 20 servers (using external switches).
ftp://ftp.compaq.com/pub/products/storageworks/techdoc/msa1000/MSACompatibilitymatrix.pdf

You can cascade the 2 switches to get up to 12 hosts single path, but you'd have to zone the passive controller out of the configuration, and you then lose redundancy (fabric and controller). So I'd guess your 7-Server (mutli-path) limit is correct if you want to maintain full redundancy.

Also check out the SAN Design Reference Guide, Chapter 4:
http://h18006.www1.hp.com/products/storageworks/san/documentation.html

Regards,

Stephen

[Mark_459]

thanks Ewe,

So even if I populate the MSA with 2 switches and 2 controllers I can really only have 7 hosts connected (short of inter switch linking to an external switch?

[Mark_459]

Stephen,

I was under the impression that the cascading of the 2 8 port switches in the MSA would work but is *unsupported* by HP.

Ideas?

[Stephen Kebbell]

Hi Mark,

as you have 2 MSA controllers, I guess it would be unsupported to cascade the switches, because then you have only one fabric, and the zoning suggestion I posted would leave your 2nd MSA controller out of the config. Then a controller failover would result in all hosts losing their storage. Uwe posted an interesting reply on another thread if you only had a single MSA Controller.
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=539894

If you have 2 controllers, 2 internal switches, then 7 is the maximum number of hosts, unless you use ISLs to external switches.

Regards,

Stephen

[Doug de Werd]

7 hosts is the max if you are running a single MSA1000 with either a single internal 2/8 switch or dual. The switches are active/passive, and are used with dual HBA sin each server (plus SecurePath of course). The internal 2/8 can be cascaded to just about any other SAN Switch for larger SAN interoperability. Just consider the internal 2/8 switch to be a B-class Brocade switch. You can even cascade 2 of the internal 2/8 switches to each other - but it requires 2 MSA1000's. You cannot cascade 2 internal 2/8 switches within a single MSA1000

Check out p. 5 of the MSA guide at:
ftp://ftp.compaq.com/pub/products/storageworks/whitepapers/16WN-0702A-WWEN.pdf

Thanks,
Doug