Storage Boards Cleanup
To make it easier to find information about HPE Storage products and solutions, we are doing spring cleaning. This includes consolidation of some older boards, and a simpler structure that more accurately reflects how people use HPE Storage.
Disk Arrays
cancel
Showing results for 
Search instead for 
Did you mean: 

Help with SC10 connection

SOLVED
Go to solution

Help with SC10 connection

Hello,
We have two L1000 hosts with two LVD SCSI on each.
Also we have two SC10 boxes with two BCC's on each. SC10 disks used for Oracle data.
What the best way to connect them to make the most high availability system?

Thank you.
13 REPLIES
Bernhard Mueller
Honored Contributor

Re: Help with SC10 connection

Hi,

you could set the SC10s in full bus mode (DIP switch setting see manual) and connect each SC10 to a SCSI card, which requires that you change the initiator target id from 7 (default) to 6 for two of the cards.
(need to reboot change at BCH in service menu with scsi command)

Then each L1000 would see all the disks in both SC10 and you could mirror from one SC10 onto the other using PVG-strict mirroring.

That would be a typical config for use in MC/SG. assume you plan to setup a cluster?

Regards,
Bernhard

Re: Help with SC10 connection


Hi,

No, not using MC/SG at the moment.

Re: Help with SC10 connection


Hi,

No, not using MC/SG at the moment.

Peter Mattei
Honored Contributor

Re: Help with SC10 connection

If you are using independent servers I strongly recommend to use both SC10 in Split-Bus mode. See the first configuration in my attached document showing the different modes.

This will isolate half of the disks to either and half to the other BCC.
Otherwise you could mount and damage the other servers disks/data!

Cheers
Peter
I love storage
Peter Mattei
Honored Contributor
Solution

Re: Help with SC10 connection

The attachment got corrupted so I try it again!
Peter
I love storage

Re: Help with SC10 connection


But before mounting disks, it's
necessary to create logical volumes at first.

So, maybe it's not so big thread for
corrupting volumes already mounted on the
other server?

Or it's something else?

Thank you.
Arturas
Peter Mattei
Honored Contributor

Re: Help with SC10 connection

Well, if a server "sees" the targets of the other it can thoretically issue SCSI commands to it and corrupt data.
You can also import the logical volumes of the other instance.
This is exactly what ServiceGuard does if it takes over. But in addition ServiceGuard acts as an arbitrator to only allow one server to access the volumes at a time!
So you can run without seperating the disks but you are prone to human errors.

Cheers
Peter
I love storage

Re: Help with SC10 connection


What impact ServiceGuard does on performance of such system?
Is it significant?

Thank you.
Art??ras

Re: Help with SC10 connection


What differences are in performance to
compare SC10 split and full bus modes
(as shown in attachments).
Peter Mattei
Honored Contributor

Re: Help with SC10 connection

ServiceGuard has almost no impact. It just takes some monitoring and heartbeat cycles of your server.

In a split Bus environment you isolate SCSI and therefore the IOs, so the servers cannot impact each other.
Anyway, in a "normal" environment you will hardly be able to notice a difference.
The more important thing is the number of disks in a volume group!

cheers
Peter
I love storage

Re: Help with SC10 connection


Can you explain your last sentence?
Peter Mattei
Honored Contributor

Re: Help with SC10 connection

Well, a single disk with 10k rpm can do 100 to 150 read-IO operations per second.
If you let's say have 20 disks, mirrored with Mirror-UX and build a volume group and spread your accesses over all disks you will have 10*100 to 150 = 1000 to 1500 read-IOs max. you can expect.
Doubling the number of disks will theoretically double the IOs you can achieve (also depends on connections, saturation of SCSI bus etc)


Peter
I love storage

Re: Help with SC10 connection


Thank you for the help.

Arturas