Enable Informix Large Chunk Feature question...

Greetings To move forward with large chunk feature for IDS940, I would do followings: 1. perform level 0 backup 2. onmode -BC 1 3. (then immediately) onmode -BC 2 4. perform another level 0 backup Does anyone have any experience with the large chunk feature that would like to share? Did anyone encounter any kinds of problems at all with this feature? Are there any additional steps that we would need to perform to ensure a successful implementation of this feature? Thanks for any inputs Kern --

I have create several 32Gb dbspaces (4 x 8Gb chunks) with no problems but this was on a >100Gb instance. Be aware that at checkpoint time oe cleaner is assigned per chunk! I did see someone on a 16 CPU machine create a 60GB chunk and load >10Gb of data into it. The load was done 16 way parallel. With 1 cleaner doing all the checkpoint work the checkpoints took >14 minutes with a 15 minute checkpoint interval! I would still use 2Gb chunks since you can now have 32000 chunks ( check onstat -d output at the end)! If you have a >2Tb instance then use 8Gb chunks. ----- Original Message ----- From: "Kern Doe" <kern_doe@yahoo.com> To: <ids@iiug.org> Sent: Wednesday, June 21, 2006 6:35 PM Subject: Enable Informix Large Chunk Feature question... [7022] > > Greetings > > To move forward with large chunk feature for IDS940, I would do > followings: > 1. perform level 0 backup > 2. onmode -BC 1 > 3. (then immediately) onmode -BC 2 > 4. perform another level 0 backup > > Does anyone have any experience with the large chunk feature that would > like > to share? > Did anyone encounter any kinds of problems at all with this feature? > Are there any additional steps that we would need to perform to ensure a > successful implementation of this feature? > Thanks for any inputs > Kern -- > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --- > [This E-mail has been scanned for viruses but it is your responsibility > to maintain up to date anti virus software on the device that you are > currently using to read this email. ] > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.394 / Virus Database: 268.9.2/372 - Release Date: 21/06/2006 > > --- [This E-mail has been scanned for viruses but it is your responsibility to maintain up to date anti virus software on the device that you are currently using to read this email. ]

I haven't had any problems related to using the large chunks. But I was able to load data after converting to large spaces. On 6/21/06, Kern Doe <kern_doe@yahoo.com> wrote: > > > Greetings > > To move forward with large chunk feature for IDS940, I would do > followings: > 1. perform level 0 backup > 2. onmode -BC 1 > 3. (then immediately) onmode -BC 2 > 4. perform another level 0 backup > > Does anyone have any experience with the large chunk feature that would > like > to share? > Did anyone encounter any kinds of problems at all with this feature? > Are there any additional steps that we would need to perform to ensure a > successful implementation of this feature? > Thanks for any inputs > Kern -- > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > >

That is the process I followed without any difficulties ... "Kern Doe" <kern_doe@yahoo.com> Sent by: ids-bounces@iiug.org 06/21/2006 01:35 PM Please respond to ids@iiug.org To ids@iiug.org cc Subject Enable Informix Large Chunk Feature question... [7022] Greetings To move forward with large chunk feature for IDS940, I would do followings: 1. perform level 0 backup 2. onmode -BC 1 3. (then immediately) onmode -BC 2 4. perform another level 0 backup Does anyone have any experience with the large chunk feature that would like to share? Did anyone encounter any kinds of problems at all with this feature? Are there any additional steps that we would need to perform to ensure a successful implementation of this feature? Thanks for any inputs Kern -- ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.

Yes, if you are using very large chunk sizes, you MUST use the fractional LRU_MIN/MAX_DIRTY settings to minimize the work done at checkpoint time. Art S. Kagel ----- Original Message ----- From: David Williams <ids@iiug.org> At: 6/21 13:57:15 I have create several 32Gb dbspaces (4 x 8Gb chunks) with no problems but this was on a >100Gb instance. Be aware that at checkpoint time oe cleaner is assigned per chunk! I did see someone on a 16 CPU machine create a 60GB chunk and load >10Gb of data into it. The load was done 16 way parallel. With 1 cleaner doing all the checkpoint work the checkpoints took >14 minutes with a 15 minute checkpoint interval! I would still use 2Gb chunks since you can now have 32000 chunks ( check onstat -d output at the end)! If you have a >2Tb instance then use 8Gb chunks. ----- Original Message ----- From: "Kern Doe" <kern_doe@yahoo.com> To: <ids@iiug.org> Sent: Wednesday, June 21, 2006 6:35 PM Subject: Enable Informix Large Chunk Feature question... [7022] > > Greetings > > To move forward with large chunk feature for IDS940, I would do > followings: > 1. perform level 0 backup > 2. onmode -BC 1 > 3. (then immediately) onmode -BC 2 > 4. perform another level 0 backup > > Does anyone have any experience with the large chunk feature that would > like > to share? > Did anyone encounter any kinds of problems at all with this feature? > Are there any additional steps that we would need to perform to ensure a > successful implementation of this feature? > Thanks for any inputs > Kern -- > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --- > [This E-mail has been scanned for viruses but it is your responsibility > to maintain up to date anti virus software on the device that you are > currently using to read this email. ] > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.394 / Virus Database: 268.9.2/372 - Release Date: 21/06/2006 > > --- [This E-mail has been scanned for viruses but it is your responsibility to maintain up to date anti virus software on the device that you are currently using to read this email. ] ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.