followup on raw chunk usage.....

Hi Art and all......Thanks for the suggestion to use fuser to determine if a process is using a raw chunk. That did help clarify what I need to do. I found a group of raw chunks (AIX 5.2 Informix 9.4) that are definitely not used by any informix instances. However....this may not be possible...but is there a way to see if these chunks have been used in the past by some process such that parts of the chunks already contain data. IE: to see if they are "used" already. I know using df does not really tell anything (although executing df -k against these chunks comes back that they are 77% used. By I am sure that is wrong and just a result of using a wrong command for a raw chunk). I guess I am wondering if there is a definitive command I could run that will accurately show if the chunk is 100% unused or not. Thanks

onstat -d will show you what chunks are currently configured. The engineopens ALL chunks at startup, so if fuser is not showing any oninit processes attached to the device/file, then it is not being used by IDS. Art On Wed, Jun 18, 2008 at 2:02 PM, WILL LANDSTROM <willlandstrom@yahoo.com> wrote: > Hi Art and all......Thanks for the suggestion to use fuser to determine if > a > process is using a raw chunk. That did help clarify what I need to do. I > found > a group of raw chunks (AIX 5.2 Informix 9.4) that are definitely not used > by > any informix instances. However....this may not be possible...but is there > a > way to see if these chunks have been used in the past by some process such > that parts of the chunks already contain data. IE: to see if they are > "used" > already. I know using df does not really tell anything (although executing > df > -k against these chunks comes back that they are 77% used. By I am sure > that > is wrong and just a result of using a wrong command for a raw chunk). I > guess > I am wondering if there is a definitive command I could run that will > accurately show if the chunk is 100% unused or not. > > Thanks > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves.

I guess the question on unused chunks is not quite as clear. Assuming you want to know if the chunk is currently attached to an informix but not containing any data, you can use onstat -d (like Art's said) look for the one where size - free <= 53 pages -- (it should contain nothing and can be dropped). ----- Original Message ---- From: Art Kagel <art.kagel@gmail.com> To: ids@iiug.org Sent: Wednesday, June 18, 2008 2:09:07 PM Subject: Re: followup on raw chunk usage..... [12452] onstat -d will show you what chunks are currently configured. The engineopens ALL chunks at startup, so if fuser is not showing any oninit processes attached to the device/file, then it is not being used by IDS. Art On Wed, Jun 18, 2008 at 2:02 PM, WILL LANDSTROM <willlandstrom@yahoo.com> wrote: > Hi Art and all......Thanks for the suggestion to use fuser to determine if > a > process is using a raw chunk. That did help clarify what I need to do. I > found > a group of raw chunks (AIX 5.2 Informix 9.4) that are definitely not used > by > any informix instances. However....this may not be possible...but is there > a > way to see if these chunks have been used in the past by some process such > that parts of the chunks already contain data. IE: to see if they are > "used" > already. I know using df does not really tell anything (although executing > df > -k against these chunks comes back that they are 77% used. By I am sure > that > is wrong and just a result of using a wrong command for a raw chunk). I > guess > I am wondering if there is a definitive command I could run that will > accurately show if the chunk is 100% unused or not. > > Thanks > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.

In case of the instance here - 2k-pagesize, IDS 9.40FC9W2 - only the first chunk of a dbspace has filled 53 pages if it contains no other data. And you cannot drop the first chunk of a dbspace. You have to drop the whole dbspace to free the chunk. Secondary chunks can be dropped if only 3 pages are filled. To say it clearly: A secondary chunk that contains more than 3 filled pages is not free and cannot surely be dropped. > -----Original Message----- > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org]On Behalf Of > Kern Doe > Sent: Wednesday, June 18, 2008 8:33 PM > To: ids@iiug.org > Subject: Re: followup on raw chunk usage..... [12453] > > > I guess the question on unused chunks is not quite as clear. > Assuming you want > to know if the chunk is currently attached to an informix but > not containing > any data, you can use onstat -d (like Art's said) look for > the one where size > - free <= 53 pages -- (it should contain nothing and can be dropped). > > ----- Original Message ---- > From: Art Kagel <art.kagel@gmail.com> > To: ids@iiug.org > Sent: Wednesday, June 18, 2008 2:09:07 PM > Subject: Re: followup on raw chunk usage..... [12452] > > onstat -d will show you what chunks are currently configured.> The engine > opens ALL chunks at startup, so if fuser is not showing any > oninit processes > attached to the device/file, then it is not being used by IDS. > > Art > > On Wed, Jun 18, 2008 at 2:02 PM, WILL LANDSTROM > <willlandstrom@yahoo.com> > wrote: > > > Hi Art and all......Thanks for the suggestion to use fuser > to determine if > > a > > process is using a raw chunk. That did help clarify what I > need to do. I > > found > > a group of raw chunks (AIX 5.2 Informix 9.4) that are > definitely not used > > by > > any informix instances. However....this may not be > possible...but is there > > a > > way to see if these chunks have been used in the past by > some process such > > that parts of the chunks already contain data. IE: to see > if they are > > "used" > > already. I know using df does not really tell anything > (although executing > > df > > -k against these chunks comes back that they are 77% used. > By I am sure > > that > > is wrong and just a result of using a wrong command for a > raw chunk). I > > guess > > I am wondering if there is a definitive command I could run > that will > > accurately show if the chunk is 100% unused or not. > > > > Thanks > > > > > > > > > > ************************************************************** > ***************** > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > -- > Art S. Kagel > Oninit (www.oninit.com) > IIUG Board of Directors (art@iiug.org) > > Disclaimer: Please keep in mind that my own opinions are my > own opinions and > do not reflect on my employer, Oninit, the IIUG, nor any > other organization > with which I am associated either explicitly or implicitly. > Neither do those > opinions reflect those of other individuals affiliated with > any entity with > which I am affiliated nor those of the entities themselves. > > > ************************************************************** > ***************** > Forum Note: Use "Reply" to post a response in the discussion forum. > > > ************************************************************** > ***************** > Forum Note: Use "Reply" to post a response in the discussion forum. >

Will - If the raw space you are investigating at some point in the past was used as an informix chunk, but is no longer being used as an informix chunk you can safely use that space for a new informix chunk. Whatever old data is left in the space will not be referenced when the new chunk is added and its chunk free list page is built - (a chunk free list page is a page in every chunk that tracks free space). The previously used space will be considered free space. Mike Always go to other people's funerals, otherwise they won't come to yours. (Yogi)