Hi Iñigo,
Thank you for your input, really appreciated.
I just had a thought; if I backup ‘pg_dump’ full database,
then restore to my new machine new postgres 8.4, which one of these programs
would work best to do the migration,
Slony, Bucardo or Londiste?
I would like to say that we did have slony and I was not
impressed, it fell behind and could not catch up and caused a very high load on
the system.
Also they way its philosophy works, it is very high
maintenance, and the idea of creating tables, and triggers on both dbs...
It might be, it was not setup properly or well, we removed
it as the db was screaming for some fresh air.
Ps I would like to point out that I am systems administrator
and not a dba, so you can understand sometimes my questions...
I think Bucardo seems best for the task, for what I have
read so far, but I do not know.
Thank you very much and I am sorry for this
Renato
Systems Administrator
e-mail: renato.oliveira@xxxxxxxxxxx
Company registered in England, registration number 658133
Registered office address:
29 Station Road,
Shepreth,
CAMBS SG8 6GB
UK
From: Iñigo Martinez Lasala
[mailto:imartinez@xxxxxxxxxxxx]
Sent: 30 March 2010 16:27
To: Renato Oliveira
Cc: pgsql-admin
Subject: RE: [ADMIN] Migrate postgres to newer hardware
Yes, you only have that two possibilities, I think.
PITR is not an option. I tested the same, from 7.4 32bit to 7.4 64bit and
didn't work. Later, when I asked here, I was told why not.
The problem with slony is that you have to manually create tables in
destination database and all database model (procedures, triggers, sequences,
views, etc). If your application creates new tables, you will have to deal with
this prior starting migration, or at least disable the creation of new tables.
Slony is asynchronous, so you will have to ensure that all changes have been
committed to new database before changing your applications or exchanging IP
addresses.
Slony also add many triggers and special tables to both databases (master and
slave). So, after migration, you will have to delete them. It's not difficult
but don't forget to do it.
By the way, are you sure your database is 160GB? Including indexes? There are
strategies in order to perform a faster pg_restore...
For example, if you migrate your database schema but don't create indexes, then
migrate data and finally create pending indexes restore will be faster. With pg
8.4 restore is very fast, so it will take less time that export.
Anyway, if you cannot leave database down for a day, I think slony will be your
best bet, although it's not exempt of problems. :)
-----Original Message-----
From: Renato Oliveira <renato.oliveira@xxxxxxxxxxx>
To: Iñigo Martinez Lasala <imartinez@xxxxxxxxxxxx>
Subject: RE: [ADMIN] Migrate postgres to newer hardware
Date: Tue, 30 Mar 2010 15:47:27 +0100
Hey Iñigo,
Thank you very much for your reply.
I would love to do just that, but unfortunately
I can’t it is not as simple as that.
I would love if the application had been built
in with this in mind…
To give you an idea; the pg_dump takes 15 hours
and I attempted a restore yesterday and it took 14 hours and 21 min.
It would not be viable for us and specially I
cannot have the system down more than maximum 30 min without the risk of losing
data and customers not having alerts.
I don’t think I will be able to use PITR to
migrate to new servers specially if it is 64 bit and to migrate to another 32
bit is no gain, as we need more memory.
As far as can gather there are only two ways:
a) Slony type
b) Pg_dump
Is that correct ? Do you guys have any other
ways?
Renato
Renato Oliveira
Systems Administrator
e-mail: renato.oliveira@xxxxxxxxxxx
Tel: +44 (0)1763 260811
Fax: +44 (0)1763 262410
www.grant.co.uk
Grant Instruments (Cambridge) Ltd
Company registered in England, registration
number 658133
Registered office address:
29 Station Road,
Shepreth,
CAMBS SG8 6GB
UK
From: Iñigo Martinez Lasala [mailto:imartinez@xxxxxxxxxxxx]
Sent:
30 March 2010 15:29
To:
Renato Oliveira
Cc:
pgsql-admin
Subject: Re: [ADMIN] Migrate postgres to newer hardware
Hi Renato.
I would follow the ancient method: perform a
pg_dump / pg_restore
Yes, you will have to take offline database for
a long period.
And yes, it would be a great moment to perform a
8.4 upgrade. Performance is far superior, restore is far faster...
... and yes, it could give you many problems if
you don't perform many test in order to address all queries without explicit
type conversions before real migration, but I think it's the best moment to
deal with a very convenient upgrade.
We have performed this upgrade last week with a
gforge (with only 25GB database) and having also to upgrade to new tsearch2 and
everything is running smooth.
-----Original Message-----
From:
Renato Oliveira <renato.oliveira@xxxxxxxxxxx>
To:
pgsql-admin@xxxxxxxxxxxxxx <pgsql-admin@xxxxxxxxxxxxxx>
Subject: [ADMIN] Migrate postgres to newer hardware
Date:
Tue, 30 Mar 2010 12:18:36 +0100
Dear All,
What would be the easiest and fastest way to
migrate Postgres 8.2.24 32 BIT to a new server 64 Bit.
The existing server runs on 32 bit architecture
and has a database as big as 160GB.
We initially thought of using PITR, but as one
of the PITR requirements is both machines need to be similar.
This similarity needs to be even in
architecture? I think I read something which says “Yes”.
If we cannot use PITR what would be the best
approach, we can’t have down time I am afraid.
Any ideas or suggestions would be very welcome.
Thank you very much
Best regards
Renato
Renato Oliveira
Systems Administrator
e-mail: renato.oliveira@xxxxxxxxxxx Tel:
+44 (0)1763 260811
Fax: +44 (0)1763 262410
www.grant.co.uk
Grant Instruments (Cambridge) Ltd
Company registered in England, registration
number 658133
Registered office address:
29 Station Road,
Shepreth,
CAMBS SG8 6GB
UK
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