An example of neat AIX stuff is the ability of a filesystem to span physical partitions. In Unix, if you only have disks of 2 GB, there's no way any partition can be more than 2 GB in size, no matter how many such disks you may have.
AIX solves this problem by pooling a set of physical disks (called Physical Volumes) into something called a Volume Group. You can then carve up the space in a Volume Group into logical disks called Logical Volumes. These logical disks can be mounted like any normal partition in Unix, and can host a filesystem.
Since a logical disk can be larger than any of the physical disks in the system, a filesystem in effect spans physical partitions.
And that's not all. You can specify each block (which IBM calls a partition!) in the logical disk to map to more than 1 block on the physical disks, and can even say that they should be on different physical disks. That's disk mirroring in software!
I don't care too much for the IBM terminology, though. I prefer to use the simple terms "physical disk", "disk pool" and "logical disk", but there's no denying the fact that their idea is an extremely good one.
Go for it, Linux!
Mail me at gcp@emirates.net.ae or at g.c.prasad@usa.net . I used to have a Hotmail account, but gave it up after it was taken over by the Evil Empire :-(.
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