Re: Migrate 2 DB's - v8.3

On Fri, May 27, 2016 at 5:09 PM, Jeff Baldwin <tarheeljeff(at)gmail(dot)com> wrote:

> Melvin,
>
> Thank you for taking the time to reply to my question.
>
> Below are the details you have requested:
>
> SOURCE:
> CentOS release 4.6
> Postgres 8.3
>
> TARGET:
> CentOS release 6.2
> Postgres 8.3
>
> Kind Regards,
> Jeff
>
> On Fri, May 27, 2016 at 5:05 PM Melvin Davidson <melvin6925(at)gmail(dot)com>
> wrote:
>
>>
>> On Fri, May 27, 2016 at 4:56 PM, Jeff Baldwin <tarheeljeff(at)gmail(dot)com>
>> wrote:
>>
>>> Hello,
>>>
>>> I am working to migrate 2 DB's (not the entire postgres instance), from
>>> 1 host to another... and I need some guidance on the best approach/practice.
>>>
>>> I have migrated ~25 other DB's in this environment, and I was able to
>>> use pg_dump/pgrestore for those, and it worked fine. These final 2 are
>>> live DB's, and I need to move them with minimal downtime (1-2hrs is
>>> acceptable).
>>>
>>> The DB's are blob DB's that are 45 and 90G in size, and are in the same
>>> Data Center, with 1G connection in between
>>>
>>> I am running postres 8.3 (I know :) ), so there may be some limitations
>>> there as well.
>>>
>>> Any help/guidance on the best way to approach this, are greatly
>>> appreciated.
>>>
>>> Kind Regards,
>>> Jeff
>>>
>>
>> Well generically speaking, since you are migrating from 8.3, you are
>> limited to pg_dump in plain format.
>> It would be nice (important) to know the PostgreSQL version you are
>> migrating to, as well as what O/S you are working with.
>>
>>
>> --
>> *Melvin Davidson*
>> I reserve the right to fantasize. Whether or not you
>> wish to share my fantasy is entirely up to you.
>>
>
OK, well since both PostgreSQL versions are the same, then you can use
custom format.

I would first by creating a testdb in the target server. Then export one
small table in customer format and verify that you can use pg_restore to
load to
the testdb. If that works, time how long a full dump takes in the old
server as a start point. Then time how long it takes to do a full load into
testdb.
You will then know how big of a window you need for migrating.

--
*Melvin Davidson*
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.