Shared disks technology with MC/SG

[Enrico Venturi]

Hello colleagues,
so far we use a shared disk technology based on SC10 system (SCSI bus); now it has been phased out.
What's the recommended technology for disk sharing in MC/SG environment? or, at least, what's the most common one?
We read about VA 7100 and VA 74xx ... actually HP suggested to use VA 7100; what's about the mirroring by using VA 7100? Is it needed to use two VA's to have mirroring?
Thanks a lot for answering to all of my questions.

Regards
Enrico

[Brian M Rawlings]

Enrico: VA7410 is a good array for this, if you only have two nodes in the cluster.

You don't need two arrays, they are built as fully redundant, with no single point of failure (dual paths, controllers, P/S, fans, and RAID protected disks).

Other advantages of arrays over JBOD for shared storage is the PVLINKS concept, that lets you assign an alternate channel to each volume, and alternate your channels so that both are used (load balancing).

Many other fully redundant arrays exist, all have these good concepts.

Regards, --bmr

[Enrico Venturi]

My clusters are composed by 3 main nodes + 1 spare node = 4 nodes.
I hope to increase the number of main nodes protected by the spare one: the previous limitation was imposed by SCSI SC10 system ...
Then, what's about VA 7410 with MC/SG and 4 or more nodes?
In any case thanks a lot for your response.
Enrico

[Christopher McCray_1]

Hello,

If you want all nodes to be active in the "failover node" role, I would suggest that you take the leap up a notch into the xp series arrays, like the xp48. Sure they cost more, but you can have up to 24 host interfaces.

Hope this helps

Chris

[John Meissner]

Our company uses EMC connected with fiber

[Enrico Venturi]

Ok, thanks for your answers but I didn't get the right one yet!

I mean: now, currently, in this moment, are there any company using the MC/SG ? What's the disk technology for the data sharing?
What's the recommended one?

thanks
Enrico

[Christopher McCray_1]

Hello,

Yes, there are a lot of companies using MC/SG. Mine, in particular, is currently using a combination of EMC symmetrics (being phased out), a tandem of two 12h autoraids, and an XP512 mass storage array, which will be the final destination of all our shared data for the 3 (soon to be 4) clusters.

As for the recommended, it depends on the amount of storage you need, the amount of money you have, and the number of nodes in your cluster. If you want all nodes to be adoptive nodes for all packages in your 3 or more node cluster, you will need something from the EMC or HP XP line.

Hope this clears things up for you.

Chris

[Enrico Venturi]

My company (Alcatel) provides equipment and solutions for the TelCo market (service providers).
We've delivered about 20 cluster composed by N+1 nodes, where N ranges from 1 to 3; N was limited only by the disk sharing technology, so far SC10 (SCSI based).
So, we were happy using SC10, unfortunately HP decided to discontinue them ... Now HP suggested to use VA 7xxx series (VA7100, VA 7410) but I'm not totally sure of this "new" solution.
I don't know XP at all. What the comparison between VA and XP?

thanks a lot
Enrico

[Christopher McCray_1 · Accepted solution]

Hello again,

The most glaring difference between the two is the size/capacity; The VAxxxx are rack mountable in your server cabinet, wheras the XP series are in their own cabinets. The VAxxxx capacity is in the 100s of GB and the XP's capacity is in the multiple TB range. The XP is also fully hardware redundant and can aaccept muliple host connections directly. You can host your entire environments storage needs centrally on one array, whether they are ServiceGuard or not.

Here's the link:

http://h18006.www1.hp.com/storage/arraysystems.html

Hope this helps

Chris