[Gluster-users] Switch recommendations

[Brian Candler]

On Mon, Jan 30, 2012 at 09:51:01PM -0500, David Coulson wrote:
> >I just looked at the Netgear website and googled for prices:
> >Two Netgear GS724TS stackable switches seem to cost nearly the same as
> >one GS748TS, both are supposed to have "a 20 Gbps, dual-ring, highly
> >redundant stacking bus".
> 
> The issue with most stacking switches is that you don't have any
> real redundancy without either doubling up on ports so each server
> is multi-homed into multiple switches, or having to manually move
> ports off a dead switch.

Or you could do a distributed replicated volume, and have one set of
replicas on one switch and another set on the other.

Incidentally, using a LAG is not going to improve your latency, and
depending on workload it might not improve your peak throughput either.  The
algorithm which distributes the frames between links is usually a hash of
src/dest MAC and/or IP addresses, so if all the traffic is between one pair
of hosts, it will all go down one link.  (Anything else might result in
packet reordering)

Depending on your requirements and budget there are now reasonably-priced
10G ethernet switches: e.g.  Netgear XSM7224S (have one here, seems to work
well, only using basic L2 functionality though).  But you need to factor in
the cost of the SFP+ NICs and the SFP+ coax cables, or fibre SFP+ modules
for longer connections.

4 of the ports on that switch can do RJ45 10G too, but don't use those for
anything latency-sensitive.

Regards,

Brian.