[Lustre-discuss] NFS vs Lustre

[Kevin Van Maren]

Nicolas Williams wrote:
> Client death with dirty data is not all that different from process
> death with dirty data in user-land.  Think of an application that does
> write(2), write(2), close(2), _exit(2), but dies between writes.
>   

It is very different; with a user application crash, all the writes to 
that point will be completed by the kernel.

With the node crash, there are no guarantees about what made it to disk 
since the last fsync() -- a later write may be partly flushed before an 
earlier write, so the node could crash after the second write made it to 
disk, but before the first one does.  But this is also true for a local 
filesystem.

Kevin