[Linux-cluster] SSI, Virtual Servers, ShareRoot, Etc

[jr]

Hi Mike,


> What I badly need right now is a shared root style system. Perhaps where all 
> nodes boot from the FC SAN using their HBA's and all have access to GFS 
> storage all around the network. 
> 
> There are various reasons I would like to do this but one of them also 
> includes trying to save on power. Say I took 32 machines and was able to get 
> them all booting off the network without drives, then I could use a 12 drive 
> FC chassis as the boot server. 
> 
> What I had worked on last year was partitioning one of these chassis into 32 
> partitions, one for each system but I think there is a better way and, maybe 
> even gaining some benefits. The problem with that was that partitions were 
> fixed and inaccessible as individual partitions once formatted on the storage 
> chassis. A shared root system would be better because then I don't have to 
> have fixed partitions, just files. Then, each node would have it's storage 
> over other storage chassis on the network. This is what I would like to 
> achieve, so far, without success.

maybe before going right into SSI which seems to be quite an effort to
get running, you might want to think about "cloning" system images by
using any kind of volume manager and copy on write volumes. lvm2 for
instance does support this. 
you basically create one master image, do all the basic configuration,
such as routes, connection to your ldap server, whatever, and then just
make snapshots of that image for every node / vm you want to create. 
you can make those snapshots writeable, which basically creates a
copy-on-write datafile. 
i hope i could help you a little bit :)
regards,
johannes

> 
> On another train of thought, I was wondering about the following. Would there 
> be any benefit in creating an SSI cluster made up of x number of servers. 
> Then, slicing that up into VM's as required. The SSI would always be intact as 
> it is, the servers could come and go as needed, the storage would be separate 
> from the entire mix. If one node needed more processing power than the rest, 
> it would take it from the SSI cluster. Otherwise, idle machines are wasting 
> their resources.