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I'm looking to deploy an application based on Oracle DB, and I was assuming that it would be possible to easily do active/passive clustering (with RH Cluster or Heartbeat) and synchronous replication a la drbd, but all the hosting providers I'm talking to are looking at me funny. Some have offered ghetto replication they called "log shipping," whereby files are asynchronously sync'd over the network, but that means that we may potentially lose up to an hour of data.

The alternative is to pay millions of dollars (well, tens to hundred of thousands) for Oracle Data Guard or somesuch.

I'm puzzled because I've worked for years on a very demanding system (tens to hundreds of GB of payment transactions) that did what I'm asking for close to $0, using PostgreSQL over DRBD over a Metropolitan Area Network.

I'm assuming here that SAN replication does the same thing as DRBD, i.e. synchronous replication where written blocks are ACK'd only after they've been written remotely. Am I wrong?

Am I missing something here?

niXar
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1 Answers1

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SAN replication does do block replication either synchronously or asynchronously. But that assumes that your hosting provider ...

a. Has purchased the SAN replication software from the SAN vendor (it isn't always included)
b. Knows how to set this up (it's pretty advanced)
c. Offers this as a service (host hosting providers don't)

Who's the hosting provider and/or the SAN vendor?

mrdenny
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  • I'm currently asking multiple providers in Europe, so I don't know exactly what equipment they have, only that one of them uses 3PAR. – niXar Sep 15 '11 at 09:55
  • Looks like that'll require that they purchase the 3PAR Remote Copy Software (http://h18006.www1.hp.com/storage/software/3par/rcs/index.html). Array replication software is usually a $20k+ purchase (plus maintenance), so odds are they won't have it in place. If you can get other array vendors names I might know if the software is an extra purchase. Array based replication is a very advanced config I wouldn't expect from most MSPs. – mrdenny Sep 15 '11 at 10:07
  • Thanks for the help, much appreciated. I'm shocked to see how expensive that stuff is compared to DRBD :/ – niXar Sep 15 '11 at 10:21
  • No problem. Yeah SAN replication software is very expensive. It's pretty cool stuff, but you have to pay for it. – mrdenny Sep 15 '11 at 10:25