Admin Tools Forum

Re: Too many chunks?

Posted By: Christine Normile
Date: Saturday, 18 August 2007, at 6:11 p.m.

In Response To: Too many chunks? (JASMINE TANG)

There is no downtime to enable large chunks on an IDS 10 system (only
IDS 10 and higher support large chunks). Enabling large chunks
simply sets a flag. When the flag is set, the page headers in the
old format are adjusted as the page is read into memory. If the page
is written to disk, it is written in the new format. So and IDS v10
database with large chunks enabled will have pages in both the old
and new format.

onmode -BC 1 allows large chunks to be created. After onmode -BC 1,
a large chunk can be created and all pages in that chunk are written
using the new page format. All other pages in the database remain in
the old format.

onmode -BC 2 means that all pages written, regardless of the chunk
they are written to, will be written in the new format. Once onmode -
BC 2 is executed, the only way to revert the server so as not to
allow big chucks is to do a level 0 restore.

Christine

Christine
On Aug 18, 2007, at 8:52 AM, JASMINE TANG wrote:

> Our system is facing a big problem that we add no more chunks
> because the no.
> of chunk reached the limit 2046.
> Vendor suggests to change to the large chunks and it affect the system
> catalogs. Any idea about it? Is it safe to do that and do that
> without any
> downtime?
>
>
> **********************************************************************
> *********
> Forum Note: Use "Reply" to post a response in the discussion forum.
>

Messages In This Thread

• Too many chunks?
  JASMINE TANG -- Saturday, 18 August 2007, at 9:52 a.m.
  • Re: Too many chunks?
    Christine Normile -- Saturday, 18 August 2007, at 6:11 p.m.
  • Re:Too many chunks?
    ART KAGEL, BLOOMBERG/ 731 LEXIN -- Monday, 20 August 2007, at 10:08 a.m.

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