connecting MCSG to SAN

[TMcB]

Hi everyone

I was wondering if you kind people could help me get my head around MCSG.
We haven’t got it in place yet, but we will be moving to a 2-node cluster early next year, so I’m starting to read into it a bit.

In place at present, we have 2 Clariion CX500 arrays (using RAID5) located in different buildings on the same campus. We will be connecting to these via fibre cards.

I’m happy enough for now with the package / monitoring concepts, but I could do with some help with the clariion integration.

The questions I have so far are :
- on the clariions can you present one LUN to more than one server
- how will the mirroring be done
- what software will I require in addition to MCSG on the HPUX servers
eg mirror view / volume manager / power path

I’m trying to get a picture in my head of how it will all be connected, but unfortunately I haven’t quite got there yet!

Any help is much appreciated

[Steven E. Protter]

Shalom,

1) Yes Clarion can present a LUN to more than 1 server.
2) Its not. The array handles redundancy and thats Raid 5. You can survive the loss of some disks, but only a limited number.
3)There is a patch set required for ServiceGuard. You will want the system patched to a recent bi-annual patch set. Finally you will need drivers for your fiber cards. If they are HP fiber cards the drivers are on the Application DC/DVD
4)If you are corrected directly you may not need any add in software such as securepath.

SEP

[TMcB]

Thank you for getting back to me Steven.

OK, so after setting up the shared VGs on the first server, I dont have to use MirrorDisk?

Also, we'll be using dual fibres to connect to the switch, how will servers know which one to use?

[Stephen Doud]

LVM can track multiple paths for a physical disk or LUN.
When creating a VG, include all paths to the disk/LUN. The /etc/lvmtab will then contain all paths, and enable LVM to use an alternate route, if one should fail.

If you forget to include alternate paths, use vgextend to include them.