RE: Clarfication on reorg of critical dbspace...
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Neil,
Some more info. The solution you suggested might not work for our
environment since we use the offsets. Here is the issue when i implement
that.
I created the DB mirroring with exact offsets and my layout looks as
follows.
Original setup
/informix/PRD/sapdata/physdev5/data8 --> INFDBV040(physical device for
PRIMARY chunk)
NOTE: Since i use offsets here, i have multiple chunks pointing to this link
with different offsets. so physdev5/data8 is distributed across 2 chunks
Chunk 1 --> rootdbs
Chunk 2 --> datadbs.
/informix/PRD/sapdata/physdev26/data4 --> INFDBV254( physical device for
MIRRORED chunk)
NOTE: on the new device, only one chunk is residing and that is the
mirrored chunk of root dbs
Chunk1 --> rootdbs.
After shutting down the system, i relocate the links to change the primary
and mirror path and the new setup looks as follows.
/informix/PRD/sapdata/physdev5/data8 --> INFDBV254(physical device for
PRIMARY chunk)
/informix/PRD/sapdata/physdev26/data4 --> INFDBV040(physical device for
MIRRORED chunk)
Here is what my problem. Now i got my database restarted without any chunk
error for rootdbs.(This was giving trouble earlier bcos i created the mirror
chunk at different offset).
But i lose chunk 2 --> datadbs of my original
path(/informix/PRD/sapdata/physdev5/data8 --> INFDBV040) at this point due
to links swap since the datadbs data doesnt exist on the new device and i
dont want to as well.
Hope you understand my problem here.
1) Is there anyway where i can say that from now onwards this is my primary
path and this is my mirror path thru onspaces for a chunk where the
mirroring is already enabled ?
Bcos if the database marks internally the swapping through a utility,
then i can disable mirroring after this and my issue can be resolved.
Hope you understand my problem here. Please pass on your suggestions
Rajesh Rajasekaran
Informix Database Administrator
Forest Pharmaceuticals Inc.
(314) 493-7073
rrajasekaran@forestpharm.com
-----Original Message-----
From: Rajasekaran, Rajesh
Sent: Thursday, July 31, 2003 8:02 AM
To: 'Neil Truby'
Cc: 'informix-list@iiug.org'
Subject: RE: Clarfication on reorg of critical dbspace...
Neil,
Also, i would like to add on some more info here. I have given my offset
start at a different place for the Mirrored volume on this chunk at first
place. Could this cause the issue when i relocate the links ?
Rajesh Rajasekaran
Informix Database Administrator
Forest Pharmaceuticals Inc.
(314) 493-7073
rrajasekaran@forestpharm.com
-----Original Message-----
From: Rajasekaran, Rajesh
Sent: Thursday, July 31, 2003 7:56 AM
To: 'Neil Truby'
Cc: informix-list@iiug.org
Subject: RE: Clarfication on reorg of critical dbspace...
Importance: High
Hi,
Thanks for your response. I have some issue when i tried to implement yr
solution.
After mirroring the data, i did the database shutdown. Relocated the
links as you suggested. After this, primary path becomes mirror path and
vice versa as explained below.
When i started the engine, it reports i/o error on both the chunks "cannot
open chunk" etc. for some reason.
When i swapped back to original setup, i mean relocated the links back to
earlier setup, and started the DB and it worked fine.
Original setup
/informix/PRD/sapdata/physdev5/data8 --> INFDBV040(physical device for
PRIMARY chunk)
/informix/PRD/sapdata/physdev26/data4 --> INFDBV254( physical device for
MIRRORED chunk)
After swapping as you suggested
/informix/PRD/sapdata/physdev5/data8 --> INFDBV254(physical device for
PRIMARY chunk)
/informix/PRD/sapdata/physdev26/data4 --> INFDBV040(physical device for
MIRRORED chunk)
Here is where i have the database initialization failure saying "cannot open
chunk:" for both the chunks.
My question is
1) Doesnt the reserved pages have the info of the original primary path and
Mirror path ? Hence when i swap, it reports errors ?
Any suggestions/comments are appreciated.
Rajesh Rajasekaran
Informix Database Administrator
Forest Pharmaceuticals Inc.
(314) 493-7073
rrajasekaran@forestpharm.com
-----Original Message-----
From: Neil Truby [mailto:neil.truby@ardenta.com]
Sent: Wednesday, July 30, 2003 2:57 PM
To: informix-list@iiug.org
Subject: Re: Clarfication on reorg of critical dbspace...
"Brice Avila" <briceavila@hotmail.com> wrote in message
news:c46e3ec5.0307301040.33fdfe@posting.google.com...
> How about restoring the rootdbs to a different location?
>
> Another thought: mirror the rootdbs, and then break the mirror. I
> don't like this suggestion so much as it makes the old original
> references dangling out in the ether forever.
>
Not at all.
Here's what you do.
Assume that the rootdbs chunk is called rootbds, and is a link to
/old_disk/rootdbs
1. Enable mirroring on your instance
2. Create a new chunk, rootdbs_m, link to /new_disk/rootdbs
3. Mirror rootdbs to rootdbs_m
Shut the engine down, and reverse the links, so rootdbs -> /new_disk/rootdbs
and rootdbs_m -> /old_disk/rootdbs
4. Start the instance
5. Drop the mirror on the root dbspace.
All done!
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<P><FONT SIZE=3D2>Neil,</FONT>
<BR><FONT SIZE=3D2> </FONT>
<BR><FONT SIZE=3D2> Some more info. The solution you suggested =
might not work for our environment since we use the offsets. Here is =
the issue when i implement that.</FONT></P>
<P><FONT SIZE=3D2> I created the DB mirroring with exact offsets =
and my layout looks as follows.</FONT>
</P>
<P><FONT SIZE=3D2> Original setup</FONT>
</P>
<P><FONT SIZE=3D2> /informix/PRD/sapdata/physdev5/data8 --> =
INFDBV040(physical device for PRIMARY chunk)</FONT>
<BR><FONT SIZE=3D2>NOTE: Since i use offsets here, i have multiple =
chunks pointing to this link with different offsets. so physdev5/data8 =
is distributed across 2 chunks</FONT></P>
<P><FONT SIZE=3D2> Chunk 1 --> rootdbs</FONT>
<BR><FONT SIZE=3D2> Chunk 2 --> datadbs.</FONT>
</P>
<P><FONT SIZE=3D2> /informix/PRD/sapdata/physdev26/data4 --> =
INFDBV254( physical device for MIRRORED chunk)</FONT>
<BR><FONT SIZE=3D2> NOTE: on the new devi