topic Re: Mixing half height and full height in same Chassis in BladeSystem - General

Mixing half height and full height in same Chassis

Andrew Crossman — Mon, 29 Mar 2010 19:50:11 GMT

I currently have 4 BL600c G5 blades in my c7000 chassis running VSphere 4.
The boss has come to me asking if we should change to half height blades for the rest of the enclosure (BL490c G6).

Can anyone see any problem with doing this?

Since they will be running VSphere, memory is my main concern not so much CPU so the half heights look like a good option.
The enclosure has 2 1/10Gb VC Enet and 2 4Gb VC/FC fibre modules in the back. How do half heights handle splitting the Network and Fibre Channel load across the modules?
If I start loading VM's onto the half height blades do I need to be wary of how many network and fiber paths I have available to the half height BL490's? Do they have access to half as much as the full height blades, since there are 2 servers taking up the space of a full height blade?
e.g the top slot uses 1 eth and 1 fibre module and the bottom slot uses the other 1 eth and 1 fibre module?

Re: Mixing half height and full height in same Chassis

The Brit — Mon, 29 Mar 2010 21:37:43 GMT

There is no issue with mixing fullheight and halfheight blades in a c7000, (I do it myself full height bl860 (itaniums) and halfheight proliants(various models)).

What you have to fully understand is the port-mapping diagrams for full and half height blades. So, for example, all onboard NICs are mapped to IC bays 1 and 2, regardless of whether the server is full or half height.

the complications come with the mappings of the Mess slots, particularly if all of your blades are going to use the FC HBA's. If you have your HBA's on MEZZ1 (full or half) then you need your FC interconnects in bays 3 & 4. If the HBA's are in Mezz 2 then you need the FC modules in bays 5 & 6.

If you have the HBA's on Mezz 3 and FC modules in bays 7 & 8, then they cannot be accessed by half height blades, you will have to move the HBA's to Mezz 1 or 2, and the FC modules to either 3 & 4, or 5 & 6.

There are other considerations, for example if you want additional NICs, then you might want to add a 4-port Ethernet Mezz card. This should be added on Mezz 2. (Mezz 1 will only map the first two ports of whatever card you put there.)

I guess the optimal config is

Mezz1 FC HBA (two Ports)--> IC Bays 3 & 4
Mezz2 Ethernet (4 ports)--> IC Bays 5, 6, 7 & 8

VC ENet modules IC Bays 1 & 2
VC FC Modules IC Bays 3 & 4
VC ENet modules IC Bays 5, 6, 7 & 8

hope this helps.

DAve.

Re: Mixing half height and full height in same Chassis

gregersenj — Tue, 06 Apr 2010 08:25:21 GMT

Yes.

You can mix full / half hight within the enclosure.
But not within the quadrandts.

The c-class are dived in quad's
C7000:
Q1 = Bay 1,2 - 9,10
Q2 = Bay 3,4 - 11,12
Q3 = Bay 5,6 - 13,14
Q4 = Bay 7,8 - 15,16

C3000:
Q1 = Bay 1,2 - 5,6
Q2 = Bay 3,4 - 7,8

The devider between the upper / lower bays, is 2 bays wide, so will have a full or half hight Quad.

The only exception, that I'm aware of, is if you've got a full hight server and a SB40c, then you will be able to user the empty bay above the SB40c for a half hight server.

Just a comment on Dave's reply.
helf hight server >> half number of connections to each interconnect.

BR
/jag

Re: Mixing half height and full height in same Chassis

Server-Support — Tue, 08 Mar 2011 22:36:39 GMT

'helf hight server >> half number of connections to each interconnect" --> does it means half port connection into the switch ?

Re: Mixing half height and full height in same Chassis

gregersenj — Wed, 09 Mar 2011 11:51:34 GMT

Yes, from each server.

Full hight servers, got 4 embedded NIC ports (LOM = LAN on motherboard)
This give you 2 ports connect to each switch.

Half hight servers got 2 LOM's. = 1 connection to each switch.

Br
/jag

Re: Mixing half height and full height in same Chassis

gregersenj — Wed, 09 Mar 2011 19:12:00 GMT

Here's some good reading:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00816246/c00816246.pdf

BR
/jag

Re: Mixing half height and full height in same Chassis

Server-Support — Wed, 09 Mar 2011 22:42:20 GMT

oh, great, thanks for the reply.

Re: Mixing half height and full height in same Chassis

Steven Clementi — Thu, 10 Mar 2011 04:53:09 GMT

As stated, you can mix up different size blades in the same chassis, with some minimal limitations.

The one thing that concerns me would be how you are going to utilize the new servers... vs. the existing environment.

If you already have a cluster with the G5's, are you planning on adding the G6's to that cluster?

if so, you may have some issues with vMotion and CPU compatibility. You may need to enable EVC on the cluster.

Also, if you are using DRS, you may want to consider having a separate cluster if your hardware configuration is going to be majorly different... (IE. amount of memory, available nics, etc.)

You will only have access to 2 physical fibre paths no matter which blade. (Server to Switch). Same amount of bandwidth.

Nic's on the other hand.. you will have at the very least.. 2 less with the half hight blades. (4 embedded on the bl6xx vs. 2 embedded on the bl490)

Other options:

Upgrade the 2 1/10GbE VC modules to Flex-10 Modules since with the 490G6 servers... you will have Flex Nics that will allow for up to 8 virtual nics (via the 2 embedded physical nics)

Steven

Re: Mixing half height and full height in same Chassis

Server-Support — Thu, 10 Mar 2011 04:54:59 GMT

wow many thanks for the great explanation mate !