[Linux-HA] Questions re: USB for HB and n-node data storage
Rudi at SoftDux.com
Mon Jul 23 07:44:30 MDT 2007
Madison Kelly wrote:
> Morning all,
> I've been mulling over how to move to an n-node cluster... I've got
> my two-node cluster working nicely, so this isn't critical. I just
> want to learn. :)
> I've not found any good docs on how to do n-node, so I've been
> trying to think of it myself (scary!). One limitation I saw was the
> backup serial link for HB. I was thinking that I would need n-1 serial
> ports per server to let all nodes talk to all other nodes, but this
> seemed problematic as I use 1U servers and I'd need to waste a
> (precious) expansion bay for a multi-port serial card (if this was
> even possible!).
> So I was wondering, is it possible to use USB for HB? I think I saw
> it mentioned that it was possible, but have seen no docs for this. If
> it is, how possible/reliable would it be to have a USB hub for n-nodes
> so that I'd only need one USB cable going into each server?
> As I understand it, DRBD only supports two nodes. I know OCFS2
> supports n-nodes as an FS, but no help if the underlying block device
> doesn't. How do people get around this limitation? I am hoping to
> avoid the need for fancy hardware, as we are a very small company.
> Would OCFS2 formatted NAS device work?
> Thanks for any pointers!
This sounds like a great idea.
I have one important question though, what type of USB cable does one
use for this type of operation? And how do you overcome the problem if 2
of the 4 node cluster is in another room (say on the second floor of the
building), or something like that?
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