IDS Forum

RE: Moving LARGE amount of data online

Posted By: Thirugnanam, Kannan
Date: Friday, 30 October 2009, at 7:22 a.m.

In Response To: Moving LARGE amount of data online (Jarrod Teale)

Is the ~450 2GB chunks stored in a SAN, if so then talk your SAN
administrator. They might be able to set up mirroring behind the scene
to mirror from faster disk subsystem to slower disk subsystem. Once the
mirror (LUNs) are in sync, they will be able to break the mirroring.
They will be able to make the mirror the primary. From the Informix
stand point, you don't even have to change the symbolic link. Caution:
Your existing SAN solution might not have this feature. There are lot of
tools available in the market from different vendors IBM/EMC/HP.

On a side note, have you thought about consolidating data in 2GB chunks
to larger chunks.

Thank you,
Kannan

-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
Jarrod Teale
Sent: Friday, October 30, 2009 5:47 AM
To: ids@iiug.org
Subject: Moving LARGE amount of data online [17839]

Hi,
RedHat EL4, 11.50.UC5
Big question here - I have ~1TB of data spread over ~450 2GB chunks in
the engine.
There are another 1000 chunks also in the engine - total is 1500 chunks.

I need to move these 450 chunks to a different disk subsystem (they need

to move from fast disk to slow disk to make room for more data).
Really easy if I shut down the engine (shut down, dd the files, move the

sym links, start up engine) - but I can't have the engine offline that
long.

So how do you move 1TB of data across 450 chunks without taking down the

engine?
I can do it through mirroring (Create a mirror, take the primary
offline, move the primary symlink, bring the primary back online and
drop the mirror).
This moves the data twice though (1. to the mirror, 2. back to the
primary).

Does anyone know how to make the mirror chunk the primary? Then I can
just create the mirrors, switch the primary and mirror (both online) and

then drop the new mirrors (original primaries).

Any other ideas to move this data without shutting down the engine? The
chunk data can be unavailable during this time - just the other 1000
chunks have to be up.

Thanks

Jarrod Teale

Team Lead - Manufacturing Execution Systems

Automation & Process Control Group

NZ Technical

Fonterra

Fonterra Extn: 77525

DDI: +64 7 850 7525

Mobile: +64 21 968 364
fax: +64 7 849 7855
email: jarrod.teale@fonterra.com
<mailto:jarrod.teale@fonterra.com>

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Messages In This Thread

• Moving LARGE amount of data online
  Jarrod Teale -- Friday, 30 October 2009, at 5:46 a.m.
  • RE: Moving LARGE amount of data online
    Thirugnanam, Kannan -- Friday, 30 October 2009, at 7:22 a.m.
  • RE: Moving LARGE amount of data online
    Norma Jean Sebastian -- Friday, 30 October 2009, at 8:01 a.m.
    • RE: Moving LARGE amount of data online
      R Fo -- Friday, 30 October 2009, at 8:26 a.m.
  • Re: Moving LARGE amount of data online
    Art Kagel -- Friday, 30 October 2009, at 10:41 a.m.

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