KAIO and Informix and HP-UX 11.0

Hi, Though I'm not subscribed to list maybe somebody is willing to help. Please reply via mail. The problem(s): 1) I'd like to enable KAIO just for testing to see, is it faster or not. System is K370 running HP-UX 11.0 and Informix 7.30 UC6 I suppose that a message should appear in MSGPATH (i.e., online.log) when Informix starts which indicate that kaio is enabled also onstat -g ioq, iov or ath doesn't show anything about kaio or kio Asyncdisk is compiled in kernel, all dbspaces are on raw partitions (including rootdbs) KAIION is set to 1 , informix user runs ksh, /dev/async has been made according to release notes. What else do I have to check? 1a) should any note about kaio appear on AIX system as well? Have never seen this on our AIX system (AIX 4.3.1 now 2, raw partitions, Informix 7.23) 2) after we switched to raw partitions, checkpoint times jumped by an order of magnitude (now sometimes 50-120 seconds) Is it normal? I tried to suppress this by setting LRU_MAX_DIRTY 5 LRU_MIN_DIRTY 2 CKPTINTVL 60 3) is the following statement true? Tune Tips for HP KAIO RESIDENCY In version 7.30 for best KAIO performance set RESIDENT flag in the onconfig to -1. In versions prior to version 7.30 set the resident flag to 1. This will reduce a significant amount of kernel locking that must be done on non-resident segments. Informix support is at little help, because they are so _slow_ and basically do something just in cases when something doesn't work at all. thanks for your attention, Ivars Strazdins State Revenue Service network administrator

Just tried it on my 10.20 server; as you can see, there's a KAIO message: You spelt KAIOON wrongly below, presumably just a typo. Did you export KAIOON? Fri Mar 12 12:20:44 1999 12:20:44 Event alarms enabled. ALARMPROG = '/opt/informixV7.24/etc/log_full.sh' 12:20:48 DR: DRAUTO is 0 (Off) 12:20:48 Requested shared memory segment size rounded from 796KB to 800KB 12:20:48 Requested shared memory segment size rounded from 796KB to 800KB 12:20:49 Informix Dynamic Server Version 7.30.UC7 Software Serial NumberAAC#J565773 12:20:49 HPUX Version B.10.20 -> Using flag/select style KAIO 12:20:49 Informix Dynamic Server Initialized -- Shared Memory Initialized. 12:20:49 Physical Recovery Started. 12:20:49 Physical Recovery Complete: 0 Pages Restored. 12:20:49 Logical Recovery Started. 12:20:51 Logical Recovery Complete. 0 Committed, 0 Rolled Back, 0 Open, 0 Bad Locks 12:20:51 Dataskip is now OFF for all dbspaces 12:20:51 On-Line Mode HTH Neil Ivars Strazdins wrote in message <7cara9$g9h$1@news.xmission.com>... > >Hi, > >Though I'm not subscribed to list maybe somebody is willing to help. Please >reply via mail. > >The problem(s): > >1) I'd like to enable KAIO just for testing to see, is it faster or not. >System is K370 running HP-UX 11.0 and Informix 7.30 UC6 > >I suppose that a message should appear in MSGPATH (i.e., online.log) when >Informix starts which indicate that kaio is enabled >also onstat -g ioq, iov or ath doesn't show anything about kaio or kio > >Asyncdisk is compiled in kernel, all dbspaces are on raw partitions >(including rootdbs) KAIION is set to 1 , informix user runs ksh, /dev/async >has been made according to release notes. What else do I have to check? > >1a) should any note about kaio appear on AIX system as well? Have never seen >this on our AIX system (AIX 4.3.1 now 2, raw partitions, Informix 7.23) > >2) after we switched to raw partitions, checkpoint times jumped by an order >of magnitude (now sometimes 50-120 seconds) > >Is it normal? >I tried to suppress this by setting > >LRU_MAX_DIRTY 5 >LRU_MIN_DIRTY 2 >CKPTINTVL 60> >3) is the following statement true? >Tune Tips for HP KAIO >RESIDENCY > In version 7.30 for best KAIO performance set RESIDENT flag > in the onconfig to -1. In versions prior to version 7.30 set the > resident flag to 1. This will reduce a significant amount of > kernel locking that must be done on non-resident segments. > >Informix support is at little help, because they are so _slow_ and basically >do something just in cases when something doesn't work at all. > >thanks for your attention, >Ivars Strazdins >State Revenue Service >network administrator

In article <7cara9$g9h$1@news.xmission.com>, Ivars Strazdins <Ivars.Strazdins@vid.gov.lv> wrote: > > Asyncdisk is compiled in kernel, all dbspaces are on raw partitions > (including rootdbs) KAIION is set to 1 , informix user runs ksh, /dev/async > has been made according to release notes. What else do I have to check? > What type of device file have you use - character or block ? The correct is character. And one more . I don't know about AIX but on HP-UX I have the following problem : with SCSI Tape Driver linked into the kernel KAIO doesn't work !!! It's corrected by some HP-UX patches. Hope this help . > 2) after we switched to raw partitions, checkpoint times jumped by an order > of magnitude (now sometimes 50-120 seconds) > > Is it normal? Checkpoint interval also depends on the physical log size and user activity ... Recommended size is 20*(max_concurrent_sessions) . > I tried to suppress this by setting > > LRU_MAX_DIRTY 5 > LRU_MIN_DIRTY 2 > CKPTINTVL 60 Setting LRU_???_DIRTY to lower values recommended, if you have long checkpoint duration (more than 10 sec.) permanently . With best regards, Juri Dovgart, Bank's "Ukraine" System Administrator; -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own

Ivars Strazdins wrote: > > Hi, > Though I'm not subscribed to list maybe somebody is willing to help. Please > reply via mail. > > The problem(s): > > 1) I'd like to enable KAIO just for testing to see, is it faster or not. > System is K370 running HP-UX 11.0 and Informix 7.30 UC6 > > I suppose that a message should appear in MSGPATH (i.e., online.log) when > Informix starts which indicate that kaio is enabled > also onstat -g ioq, iov or ath doesn't show anything about kaio or kio > > Asyncdisk is compiled in kernel, all dbspaces are on raw partitions > (including rootdbs) KAIION is set to 1 , informix user runs ksh, This environment var is KAIOON=1 and make sure it is exported (this is not an ONCONFIG parameter BTW. [SNIP] > 2) after we switched to raw partitions, checkpoint times jumped by an order > of magnitude (now sometimes 50-120 seconds) > > Is it normal? Yes it is expected. Using COOKED files the filesystem is caching your output and flushing the cache in the background so the filesystem returns to the engine immediately so the engine thinks the checkpoint is complete and though it writes the files in OSYNC mode so they flush immediately the flush is asynchronous and the engine does not know to wait for the flush to complete. With RAW files there is not OS caching so the engine writes directly to disk and has to wait for the writes to complete. You can speed this by getting SCSI controllers with large non-volatile cache so the writes are cached by the controller but guaranteed by the cache battery backup. > 3) is the following statement true? > Tune Tips for HP KAIO > RESIDENCY > In version 7.30 for best KAIO performance set RESIDENT flag > in the onconfig to -1. In versions prior to version 7.30 set the > resident flag to 1. This will reduce a significant amount of > kernel locking that must be done on non-resident segments. Yes true. Residency is very important. As of 7.30 RESIDENT can take any of several values. RESIDENT => -1 locks the first virtual segment as well as the resident segment. IDS before 7.30 only locks the resident segment. Art S. Kagel

"Art S. Kagel" wrote: > Ivars Strazdins wrote: > > > > Hi, > > > Though I'm not subscribed to list maybe somebody is willing to help. Please > > reply via mail. > > > > The problem(s): > > > > 1) I'd like to enable KAIO just for testing to see, is it faster or not. > > System is K370 running HP-UX 11.0 and Informix 7.30 UC6 > > > > I suppose that a message should appear in MSGPATH (i.e., online.log) when > > Informix starts which indicate that kaio is enabled > > also onstat -g ioq, iov or ath doesn't show anything about kaio or kio > > > > Asyncdisk is compiled in kernel, all dbspaces are on raw partitions > > (including rootdbs) KAIION is set to 1 , informix user runs ksh, > This environment var is KAIOON=1 and make sure it is exported (this is > not an ONCONFIG parameter BTW. > > [SNIP] > > > 2) after we switched to raw partitions, checkpoint times jumped by an order > > of magnitude (now sometimes 50-120 seconds) > > > > Is it normal? > > Yes it is expected. Using COOKED files the filesystem is caching your > output and flushing the cache in the background so the filesystem > returns to the engine immediately so the engine thinks the checkpoint > is complete and though it writes the files in OSYNC mode so they flush > immediately the flush is asynchronous and the engine does not know to > wait for the flush to complete. With RAW files there is not OS caching > so the engine writes directly to disk and has to wait for the writes to > complete. You can speed this by getting SCSI controllers with large > non-volatile cache so the writes are cached by the controller but > guaranteed by the cache battery backup. > > > 3) is the following statement true? > > Tune Tips for HP KAIO > > RESIDENCY > > In version 7.30 for best KAIO performance set RESIDENT flag > > in the onconfig to -1. In versions prior to version 7.30 set the > > resident flag to 1. This will reduce a significant amount of > > kernel locking that must be done on non-resident segments. > > Yes true. Residency is very important. As of 7.30 RESIDENT can take > any of several values. RESIDENT => -1 locks the first virtual segment > as well as the resident segment. IDS before 7.30 only locks the > resident segment. > > Art S. Kagel