[Linux-cluster] Distributed Storage in Cluster Suite

[Joseph L. Casale]

>That largely depends on what exactly you want to do.
>You could export storage space via iSCSI and apply CLVM on top of that. 
>IIRC CLVM can now handle mirroring.
>
>It's nowhere nearly as good as DRBD, though - that provides a very 
>comprehensive solution for most eventualities you might face, including 
>post-outage resync.
>
>Why, exactly, would you want to limit yourself to only what is in the 
>distro? DRBD builds cleanly into RPM packages, I use it on a number of 
>systems with GFS on top.

Hi Gordan,
I'm under the gun to get something operational asap and have been reading like
mad but given the severity of getting it wrong, I want some experience under my
belt before I step off the reservation. I don't have the infrastructure available
to export an iscsi device, it's the backend I need redundant just the way drbd
would provide.

I am ok with drbd, but its integration with rhcs concerns me as I don't really
know how the init scripts get constructed. I saw an archive post about the wrapper
for /usr/share/cluster/drbd.sh to hand it the resource name.

I can assume if a node tanks, drbd goes primary on the remaining node, everything
is good.

Looking through drbd.sh I see case's for promote/demote, I added this (the wrapper actually)
as a resource "script" with a child "fs" in a mock cluster as the underlying device
was primary on that node, it just started:) How does rhcs know when adding a "script"
to pass the required cases? How do I configure this?

Thanks guys, it's been a mountain of info the last few days so bear with me!
jlc