On Tue, Jul 10, 2012 at 6:28 AM, Shaun Thomas <sthomas@optionshouse.com> wrote:
> On 07/10/2012 01:11 AM, Daniel Farina wrote:
>
>> So if I get this straight, what you are saying is "be asynchronous
>> replication unless someone is around, in which case be synchronous"
>> is the mode you want.
>
>
> Er, no. I think I see where you might have gotten that, but no.
From your other communications, this sounds like exactly what you
want, because RAID-1 is rather like this: on writes, a degraded RAID-1
needs not wait on its (non-existent) mirror, and can be faster, but
once it has caught up it is not allowed to leave synchronization,
which is slower than writing to one disk alone, since it is the
maximum of the time taken to write to two disks. While in the
degraded state there is effectively only one copy of the data, and
while a mirror rebuild is occurring the replication is effectively
asynchronous to bring it up to date.
--
fdr