On 09/08/10 8:02 PM, Lazaro Ruben Garcia Martinez wrote:
> Thank you very much for your answer, In the cluster that i said before
> I need only failover.
> In the documentation of postgresql I read about the Shared Disk
> Failover, this tecnique avoids synchronization overhead by having only
> one copy of the database. It uses a single disk array that is shared
> by multiple servers. If the main database server fails, the standby
> server is able to mount and start the database as though it was
> recovering from a database crash. This allows rapid failover with no
> data loss. One disadvantage is that the standby server should never
> access the shared storage while the primary server is running.
>
> For these resons is posible to use a SAN?
sure.
you'll also want cluster management software to coordinate that, such as
Heartbeat, Veritas Cluster Service, etc. most vendors who design
failover clusters use some sort of storage fencing, such that the
standby host *can't* access the shared storage until the 'fencing' is
switched. this is often done via port disable on a managed switch (FC
or Ethernet).