Are there any single point of failures in HP BL870c + c3000 enclosure

[Amit Jindal_1]

Hi,
We are trying to upgrade our project infrastructure ( current PA RISC ) to integrity blades. As the data is of financial importance we are trying to search some hardware which has no SPOF, but at the same time we don't have high budget to buy Superdomes.

So could anyone please let me know what the potential SPOF's in bl870c + c3000 or c7000 enclosure. I am searching hp sites but unable to get some valid document.

Thanks ..

[Torsten.]

To avoid SPOF you should consider to create a serviceguard cluster! Double everything (server, switches, storage).

[HEM_2]

a c3000 would create a single point of failure with the network connections.

BL870cs have 4 embedded NIC ports and if you install this blade in to a c3000, all 4 of the NICs would map to I/O Bay 1. This means whatever is in Bay 1 for an Interconnect would be a single point of failure. Another option here would be to buy a Mezzanine card for the BL870C and a 2nd Interconnect Switch for I/O Bay 2

In a c7000, 2 of the NICs go to I/O Bay 1 and 2 of them go to I/O bay 2 to eliminate a single point of failure. You could run Service Guard and connect the Interconnects in Bay 1 and Bay 2 to separate external switches.

[Amit Jindal_1]

Thanks HEM for the detail answer. Still I will wait for some more answers.

I am not in a position to use Service guard at this moment. But am looking from hardware point of view for any spof's.

I found from hp sites that cpu, mem and I/O channel are not having any SPOF inside the blade. So it seems better to use the c7000 enclosure. I was thinking from the blade point of view only, but now i have to see the enclosure as well for any spof.

But this bl870 c can have 3 mezannine slots, that means i can use two HBA cards and another ethernet card. Is that all I get only 3 slots for additional devices ?

[JeffWardlaw]

The midplane on a c7000 can fail. Mine did last summer. Had to bring the whole cage down to replace it. If you're going to invest in the enclosure, make sure to buy two.

[Torsten.]

3 mezzanine slots are a lot - since there are already 4 NICS built-in. You need FC, but what else?

IMHO a single server is always a SPOF, because hardware can fail and OS can be down. Same for most storage arrays and SANs too. That's why I said "double everything", in this case 2 enclosures, 2 servers, 2 arrays forming 2 SANs.

[The Brit · Accepted solution]

Amit,
Unless you have fairly deep pockets, there are almost always SPOF. For a single c3000, no matter how you configure it, there is always the backplane.

Leaving that aside, you dont mention which OS you are going to use, which could have a significant bearing on whether SPOF's can be avoided (given that you say that serviceguard is not an option). You would at least need somekind of clustering for your blades, and the ability to handle multipathed storage devices (seamlessly).

Anyway, for a single c3000 with bl870c full height blades, you should consider the following.

1. All of your onboard NICs map to IC Bay 1.
2. The ports on MEZZ1 maps to IC Bay 2.
3. The ports on MEZZ2 & MEZZ3 map to IC Bays 3 & 4.

There is a backplane stacking link between IC Bays 1 & 2, so if both contain VC ENet modules, then you will have VC manager failover. Also, if IC 1 & 2 are both ENet, then you can set up NIC teaming between Onboard NICs and MEZZ1 NICs. This will make you Network communication pretty solid.

If you have FC HBA's in MEZZ2 and MEZZ3, and VC FC in IC Bay 3 and 4, AND your OS can handle multipath storage devices, then your SAN connectivity should also be pretty solid.

I would also recommend installing a full compliment of Fans and Power Supplies, they are relatively cheap, and provide peace of mind.

Hope this helps.

Dave

[Amit Jindal_1]

Thanks Dave and aall of you as well for sharing your experience and answers.

Planning to use HP UX 11i v3. we are planning to use two enclosures ( c7000 with 4 bl870c each ). Not planning to use any virtualization or vpar feature.

One more question: If i get 2 HBA cards possibly dual ports and with multipath i get eventually 2 ports. Will that hold good for around 8 to 10 TB of storage per blade. About 60 % is historic data so transctions for those, for 4 TB there could be active transctions day to day.

[Amit Jindal_1]

sorry one typo in my earlier reply:

About 60 % is historic data so transctions for those, for 4 TB there could be active transctions day to day.

should be raed as :
About 60 % is historic data so NO transctions for those on daily basis, for 4 TB there could be active transctions day to day.