Re: checkpoint spikes

Art: But if all the chunks are raw and KAIO is enabled, then you only need 1 or 2 AIOVPS for logging.........Correct? thanks Allen "Art S. Kagel & Family" wrote: > > Arshad, Shehla wrote: > > > > Mark, > > > > I have been making use of LRU Contention script that you provided > > (Thanks!!), to check LRU contention on one of our servers. LC (spi*100/buf) > > is mostly more than 5 at busier times. We have increased the number of LRUS > > and CLEANERS to 127 but it seems there have been little or no effect on LRU > > contention. What are we missing here? What else can be changed? > > > > We are running IDS 7.30.FC7 on HP-UX 11 with 10 cpus given to this instance. > > There are 300000 Buffers, 40 AIOVPS, 135 Chunks, 28 disks. Please advise. > [SNIP] > > If you have 135 chunks you should have 135 AIO VPs plus a few for overhead > and logging plus one extra for each heavily hit chunk. This > is for 7.30+, for 7.2x make that 1.5 AIO VPs per chunk and for 7.1x > 2 AIO VPs per chunk. > > -- > Art S. Kagel & Family > kagel@erols.com

You don't need any AIO VP for logging just for writes to cooked files. If you have cooked log space you will be using LIO vps not AIO vps. However, I would definitely recomend moving to raw disks and KAIO before setting up 135 AIO VPS. Also, you need to take into consideration the speed of the disks and how many chunks you have on each disk before assigning 1 AIO VP for each chunk. 135 AIO vps with 28 disks would probably create an issue with disk contention. If you are running SAP, sorry they don't support KAIO. For what it's worth, take it of leave it. "allenj" <allenj@ndr.com> wrote in message news:38E50D11.624A73F3@ndr.com... > Art: > > But if all the chunks are raw and KAIO is enabled, then you only need 1 > or 2 AIOVPS for logging.........Correct? > > thanks > > Allen > > "Art S. Kagel & Family" wrote: > > > > Arshad, Shehla wrote: > > > > > > Mark, > > > > > > I have been making use of LRU Contention script that you provided > > > (Thanks!!), to check LRU contention on one of our servers. LC (spi*100/buf) > > > is mostly more than 5 at busier times. We have increased the number of LRUS> > > and CLEANERS to 127 but it seems there have been little or no effect on LRU > > > contention. What are we missing here? What else can be changed? > > > > > > We are running IDS 7.30.FC7 on HP-UX 11 with 10 cpus given to this instance. > > > There are 300000 Buffers, 40 AIOVPS, 135 Chunks, 28 disks. Please advise. > > [SNIP] > > > > If you have 135 chunks you should have 135 AIO VPs plus a few for overhead > > and logging plus one extra for each heavily hit chunk. This > > is for 7.30+, for 7.2x make that 1.5 AIO VPs per chunk and for 7.1x > > 2 AIO VPs per chunk. > > > > -- > > Art S. Kagel & Family > > kagel@erols.com

Greg, About SAP, I beg to differ. SAP says not to use KAIO on HP prior to Informix release 7.30. However, after 7.30, they do include instructions on how to set it up and documentation on the 'out of resources' problem and how to adjust for it. For example, see OSS note 37106. Doug Agnew "Greg Alan DeWinter" <dewinter@itg-consulting.com> wrote in message news:UbeF4.11100$9m6.418963@newsread1.prod.itd.earthlink.net... > You don't need any AIO VP for logging just for writes to cooked files. If > you have cooked log space you will be using LIO vps not AIO vps. However, > I would definitely recomend moving to raw disks and KAIO before setting up > 135 AIO VPS. Also, you need to take into consideration the speed of the > disks and how many chunks you have on each disk before assigning 1 AIO VP > for each chunk. 135 AIO vps with 28 disks would probably create an issue > with disk contention. If you are running SAP, sorry they don't support > KAIO. > > For what it's worth, take it of leave it. > > > > "allenj" <allenj@ndr.com> wrote in message news:38E50D11.624A73F3@ndr.com... > > Art: > > > > But if all the chunks are raw and KAIO is enabled, then you only need 1 > > or 2 AIOVPS for logging.........Correct? > > > > thanks > > > > Allen > > > > "Art S. Kagel & Family" wrote: > > > > > > Arshad, Shehla wrote: > > > > > > > > Mark, > > > > > > > > I have been making use of LRU Contention script that you provided > > > > (Thanks!!), to check LRU contention on one of our servers. LC > (spi*100/buf) > > > > is mostly more than 5 at busier times. We have increased the number of > LRUS> > > > and CLEANERS to 127 but it seems there have been little or no effect > on LRU > > > > contention. What are we missing here? What else can be changed? > > > > > > > > We are running IDS 7.30.FC7 on HP-UX 11 with 10 cpus given to this > instance. > > > > There are 300000 Buffers, 40 AIOVPS, 135 Chunks, 28 disks. Please > advise. > > > [SNIP] > > > > > > If you have 135 chunks you should have 135 AIO VPs plus a few for > overhead > > > and logging plus one extra for each heavily hit chunk. This > > > is for 7.30+, for 7.2x make that 1.5 AIO VPs per chunk and for 7.1x > > > 2 AIO VPs per chunk. > > > > > > -- > > > Art S. Kagel & Family > > > kagel@erols.com > >

allenj wrote: > > Art: > > But if all the chunks are raw and KAIO is enabled, then you only need 1 > or 2 AIOVPS for logging.........Correct? Just a few yes, Informix suggests a maximum of 6 plus one for each chunk which is NOT a RAW device (ie a COOKED device or FS file). You will need at least 2 AIO VPs one for writting to the message log and one for the console log messages. Most KAIO users configure 2-4 AIO VPS. Art S. Kagel > thanks > > Allen > > "Art S. Kagel & Family" wrote: > > > > Arshad, Shehla wrote: > > > > > > Mark, > > > > > > I have been making use of LRU Contention script that you provided > > > (Thanks!!), to check LRU contention on one of our servers. LC (spi*100/buf) > > > is mostly more than 5 at busier times. We have increased the number of LRUS > > > and CLEANERS to 127 but it seems there have been little or no effect on LRU > > > contention. What are we missing here? What else can be changed? > > > > > > We are running IDS 7.30.FC7 on HP-UX 11 with 10 cpus given to this instance. > > > There are 300000 Buffers, 40 AIOVPS, 135 Chunks, 28 disks. Please advise. > > [SNIP] > > > > If you have 135 chunks you should have 135 AIO VPs plus a few for overhead > > and logging plus one extra for each heavily hit chunk. This > > is for 7.30+, for 7.2x make that 1.5 AIO VPs per chunk and for 7.1x > > 2 AIO VPs per chunk. > > > > -- > > Art S. Kagel & Family > > kagel@erols.com -- Art S. Kagel & Family kagel@erols.com