Thinking of Pool data structures..

For the past 2 days, I and Krishna were thinking about the structure of the pool. Went well. Many ideas came up. To handle pool, there should be 2 data structures.

• one for physical on_disk pool. (when the pool info is saved in disks, we should take care of : 'this' data is from 'this' sector to 'this' sector. )
  
  
• one for memory (take information from physical disks and put it in the pool object in memory which is handy for programming.)
  

These things are going fine. Once they are clearly defined, I'll put them up here. We also came up with a few problems we might be facing.

1. How can a disk (partition or physical disk or whatever) be uniquely identified ? The device address (like /dev/sda) might change if you reboot.
   
   
2. When the computer is rebooted, our pool should know what all disks it was handling before. For this we need to store the pool-device relationship somewhere permanently (you cant store it in disk which is participating in pool because it can be removed). Where can I save that ?
   
   
3. (!) Lot of things become easy if we keep a maximum limit on the disk that can participate in the pool ( say 256 ).. May be there are ways to handle infinite number of disks, but to begin with, the first version will have 256 as limit.