Chris Mavin wrote:
Can someone clarify the following for me.
I'm using Glusterfs RC 2.
If I am using the HA translator rather than AFR, Does this expect to be
using a shared storage accessible from both servers?
Put another way, is the HA translator simply a way of providing High
availability for a SAN?
When I test it using 2 servers the active server is written to fine but
the backup server simply gets a 0 byte file written to it.
HA is, afaik, just a way to switch communications between target
machines - it does not itself have any sort of replication features, nor
does it have the ability to speak to multiple targets simultaneously.
Given three machines :
- ClientA
- ServerA
- ServerB
If ClientA is configured to communicate to ServerA & ServerB via HA, it
will pick one (ServerA, for example), and speak to it exclusively until
such a time as ServerA stops working - whereupon it will communicate
with ServerB.
Nowhere in that scenario is data replicated or copied between ServerA
and ServerB. For this, you'd either need to set up server-side AFR
between ServerA and ServerB (and keep HA on ClientA), or set up
client-sde AFR on ClientA (and ditch HA altogether).
--
Daniel Maher <dma+gluster AT witbe DOT net>
