[Beowulf] network filesystem

[Bruce Allen]

Hi Stu,

> Actually I run it (Lustre) in production and I'm not a kernel hacker.

Thank you for this snapshot of 'real world' Lustre use. At the risk of 
hijacking this thread (or borrowing it...) could I ask you a question 
about Lustre?  I've always been interested in Lustre but never used it.

Like everyone in this mailing list I am interested in a distributed 
filesystem whose bandwidth and speed are commensurate with the total raw 
hardware IO performance of the disks and the network speed and 
intersection bandwidth.  But there are two additional features that I also 
think would be very desirable:

(1) RAID-across-nodes.  For example every ten nodes form a redundant RAID 
set.  The disappearance of any one of these nodes causes no data loss, 
service loss, or corruption at the user level.  The total redundant 
storage available from the ten nodes is 90% of the available raw storage.

(2) Symmetry: all nodes have identical behavior and features.  There are 
no specialized IO or metadata nodes, which act as filesystem bottlenecks 
and which are single points of failure.

Am I correct that Lustre does not offer either of these features?

Do you (or does someone else) know if there is an open-source or 
commercial distributed (posix) filesystem with these features?

Cheers,
 	Bruce