If say I have a BladeCenter S chassis and 2x BladeCenter Server HS22. I want to have a backup storage with this two.. what should I buy? what are my options? does it have to be IBM products? or any disk will work?
Another option is to backup the disks in your blades across the network to some inexpensive system with lots of hard drives.
It's also possible to have the bootup hard drives for the blades somewhere else across the network using iSCSI. Linux supports iSCSI, so you could buy a cheap desktop, install Linux and a bunch of drives and the blades could mount those drives via iSCSI, using them for either system drives or backup drives.
If I've left out anything, I would be happy to clarify.