Re: memory usage by dbw very high
what is meant by OP,tanel.. Original Poster. Tanel.
Re: memory usage by dbw very high
hi tanel and mladen not every time a process is started does it swap but sometimes swapping does happen.(this is from the top o/p which shows a increase in the memory used in swap.).how do we check whether a single process swaps or not? and the dbw process is using more % of memory than a couple of days back.(o/p pf ps aux). is this how linux kernel works or is there something else i can check. thanks sai what is meant by OP,tanel.. Tanel Poder [EMAIL PROTECTED] wrote: Thanks Mladen, that was a good tip about linux kernel enhancement, howeverOP still uses 2.4.9 as stated in original post.I just wanted to know whether OP actually sees excessive paging or justmemory being "full", the latter one, as you know, isn't really a problem.Tanel.- Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>Sent: Saturday, November 01, 2003 5:39 PM The whole thing comes as a consequence of using buffered I/O. New linux kernels (2.4.18 and later) have new memory management, which allows the kernel to grab more memory for buffers in periods of intense I./O activity. If you have a very active database on ReiserFS or Ext3, Linux is going to try to help you out by allocating more memory for the file system buffers, even by stealing! pages from the active processes, which will, in turn. start paging. The only possible response is to eliminate thebuffered I/ O and switch to non-buffered I/O. That is not so hard to do. On 2003.11.01 09:44, Tanel Poder wrote: Just for clarification, do you actually see swapping when starting a new process or you just guess linux would swap because you don't see "free" memory in top output? Tanel. - Original Message - From: Sai Selvaganesan To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 1:34 AM Subject: RE: memory usage by dbw very highrich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08)is used by non shared memory size. i went thru all the processes and found dbwr u! sing the max %mem. what could be the reason? sai "Jesse, Rich" <[EMAIL PROTECTED]>wrote: If I'm not mistaken, this figure includes the size of the sharedmemory segment from the SGA. Take the output of the "oracle" line of"ipcs -a" (hopefully you'll only have one!) and subtract it from the processsize to get a better idea of the non-shared memory size of the process. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA-Original Message- Sent: Friday, October 31, 2003 3:49 PM To: Multiple recipients of list ORACLE-Lhi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swappingwhen any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp o/p from top: 1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35 132 proces! ses: 131 sleeping, 1 running, 0 zombie, 0 stopped CPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idle CPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idle CPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idle CPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idle Mem: 3089964K av, 3083380K used, 6584K free, 846848K shrd, 193448K buff Swap: 2048152K av, 1652K used, 2046500K free 1852468K cached sga size: Total System Global Area 1084823632 bytes Fixed! Size 452688 bytes Variable Size 335544320 bytes Database Buffers 738197504 bytes Redo Buffers 10629120 bytes pga aggregate size:700M and ps o/p of dbw process USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND oracle 4062 0.0 16.4 1131260 508168 ? S 10:16 0:06 ora_dbw0_revenue please advise. what is really going on. thanks sai -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services- To REMOVE yourself from this mailing list, send a! n E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Mladen Gogala Oracle DBA -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Mladen Gogala INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, i
Re: memory usage by dbw very high
mladen i have gtop...and i am trying to get thru the preferences which u have mentioned. 1. can you please help me to find the kernel mode for the processes. 2. on this linux box i see that demon kswapd and bdflush in the process list.should they always be running or do they get intiated only when paging or swapping happens. thanks sai Mladen Gogala [EMAIL PROTECTED] wrote: What we have here is a confusion with terminology. Process cannot "be swapping". When there is a serious shortage of memory, the swap demon(yes, your Unix box is haunted) known by the horrible name of [kswapd] writes the whole address space space belonging to the process onto swap. At that point, process is swapped.Unless, we are talking about the kswapd process, the process cannot "be swapping". Kernelswap demon seldomly uses oracle database.Process can be paging. When there is serious shortage of memory (but less serious then inthe first case), pages are stolen from the process and written onto the swap. It's called"page replacement". When processes need pages that have been thrown out of memory by the page replacement demon (in case of Linux, it's called bdflush but on some unix implementations,there is a process called "updated" or ! "paged " which performs this function.), it pages them in.If the page is in memory (buffer cache would a good place to look), we're talking about the soft page fault. If the page has to be read from the disk, we're talking about hard pagefault. Processes that page get charged for a lot of CPU time, all of it in the kernel mode.If you have gtop (my kindest advice is to get it), you can set preferences and see kernel modefor the processes. Ones consuming large amounts of the kernel mode are ones that are paging.On 11/03/2003 01:24:27 PM, Sai Selvaganesan wrote: hi tanel and mladen not every time a process is started does it swap but sometimes swapping does happen.(this is from the top o/p which shows a increase in the memory used in swap.).how do we check whether a single process swaps or not? and the dbw process is using more % of memory than a couple of days back.(o/p pf ps aux). is this how linux kernel works or is th! ere something else i can check. thanks sai what is meant by OP,tanel.. Tanel Poder <[EMAIL PROTECTED]>wrote: Thanks Mladen, that was a good tip about linux kernel enhancement, however OP still uses 2.4.9 as stated in original post. I just wanted to know whether OP actually sees excessive paging or just memory being "full", the latter one, as you know, isn't really a problem. Tanel. - Original Message - To: "Multiple recipients of list ORACLE-L" Sent: Saturday, November 01, 2003 5:39 PMThe whole thing comes as a consequence of using buffered I/O. New linux kernels (2.4.18 and later) have new memory management, which allows the kernel to grab more memory for buffers in periods of intense I./O activity. If you have a very active database on ReiserF! S or Ext3, Linux is going to try to help you out by allocating more memory for the file system buffers, even by stealing pages from the active processes, which will, in turn. start paging. The only possible response is to eliminate the buffered I/ O and switch to non-buffered I/O. That is not so hard to do. On 2003.11.01 09:44, Tanel Poder wrote: Just for clarification, do you actually see swapping when starting a new process or you just guess linux would swap because you don't see "free" memory in top output? Tanel. - Original Message - From: Sai Selvaganesan To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 1:34 AM Subject: RE: memory usage by dbw very high ! rich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08) is used by non shared memory size. i went thru all the processes and found dbwr using the max %mem. what could be the reason? sai "Jesse, Rich" wrote: If I'm not mistaken, this figure includes the size of the shared memory segment from the SGA. Take the output of the "oracle" line of "ipcs -a" (hopefully you'll only have one!) and subtract it from the process size to get a better idea of the non-shared memory size of the process. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Su! ssex, WI USA -Original Message- Sent: Friday, October 31, 2003 3:49 PM To: Multiple recipients of list ORACLE-L hi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swapping when any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp o/p from top: 1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35 132 proces! ses: 131 sleeping, 1 running, 0 zombie, 0 stopped CPU0 states: 24.4% user, 2.2% system,
Re: memory usage by dbw very high
Preferences-Process Fields-STime, UTime. On 11/03/2003 02:44:34 PM, Sai Selvaganesan wrote: mladen i have gtop...and i am trying to get thru the preferences which u have mentioned. 1. can you please help me to find the kernel mode for the processes. 2. on this linux box i see that demon kswapd and bdflush in the process list.should they always be running or do they get intiated only when paging or swapping happens. thanks sai Mladen Gogala [EMAIL PROTECTED] wrote: What we have here is a confusion with terminology. Process cannot be swapping. When there is a serious shortage of memory, the swap demon (yes, your Unix box is haunted) known by the horrible name of [kswapd] writes the whole address space space belonging to the process onto swap. At that point, process is swapped. Unless, we are talking about the kswapd process, the process cannot be swapping. Kernel swap demon seldomly uses oracle database. Process can be paging. When there is serious shortage of memory (but less serious then in the first case), pages are stolen from the process and written onto the swap. It's called page replacement. When processes need pages that have been thrown out of memory by the page replacement demon (in case of Linux, it's called bdflush but on some unix implementations, there is a process called updated or paged which performs this function.), it pages them in. If the page is in memory (buffer cache would a good place to look), we're talking about the soft page fault. If the page has to be read from the disk, we're talking about hard page fault. Processes that page get charged for a lot of CPU time, all of it in the kernel mode. If you have gtop (my kindest advice is to get it), you can set preferences and see kernel mode for the processes. Ones consuming large amounts of the kernel mode are ones that are paging. On 11/03/2003 01:24:27 PM, Sai Selvaganesan wrote: hi tanel and mladen not every time a process is started does it swap but sometimes swapping does happen.(this is from the top o/p which shows a increase in the memory used in swap.).how do we check whether a single process swaps or not? and the dbw process is using more % of memory than a couple of days back.(o/p pf ps aux). is this how linux kernel works or is there something else i can check. thanks sai what is meant by OP,tanel.. Tanel Poder wrote: Thanks Mladen, that was a good tip about linux kernel enhancement, however OP still uses 2.4.9 as stated in original post. I just wanted to know whether OP actually sees excessive paging or just memory being full, the latter one, as you know, isn't really a problem. Tanel. - Original Message - To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 5:39 PM The whole thing comes as a consequence of using buffered I/O. New linux kernels (2.4.18 and later) have new memory management, which allows the kernel to grab more memory for buffers in periods of intense I./O activity. If you have a very active database on ReiserFS or Ext3, Linux is going to try to help you out by allocating more memory for the file system buffers, even by stealing pages from the active processes, which will, in turn. start paging. The only possible response is to eliminate the buffered I/ O and switch to non-buffered I/O. That is not so hard to do. On 2003.11.01 09:44, Tanel Poder wrote: Just for clarification, do you actually see swapping when starting a new process or you just guess linux would swap because you don't see free memory in top output? Tanel. - Original Message - From: Sai Selvaganesan To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 1:34 AM Subject: RE: memory usage by dbw very high rich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08) is used by non shared memory size. i went thru all the processes and found dbwr using the max %mem. what could be the reason? sai Jesse, Rich wrote: If I'm not mistaken, this figure includes the size of the shared memory segment from the SGA. Take the output of the oracle line of ipcs -a (hopefully you'll only have one!) and subtract it from the process size to get a better idea of the non-shared memory size of the process. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA -Original Message- Sent: Friday, October 31, 2003 3:49 PM To: Multiple recipients of list ORACLE-L hi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swapping when any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp
Re: memory usage by dbw very high
What we have here is a confusion with terminology. Process cannot be swapping. When there is a serious shortage of memory, the swap demon (yes, your Unix box is haunted) known by the horrible name of [kswapd] writes the whole address space space belonging to the process onto swap. At that point, process is swapped. Unless, we are talking about the kswapd process, the process cannot be swapping. Kernel swap demon seldomly uses oracle database. Process can be paging. When there is serious shortage of memory (but less serious then in the first case), pages are stolen from the process and written onto the swap. It's called page replacement. When processes need pages that have been thrown out of memory by the page replacement demon (in case of Linux, it's called bdflush but on some unix implementations, there is a process called updated or paged which performs this function.), it pages them in. If the page is in memory (buffer cache would a good place to look), we're talking about the soft page fault. If the page has to be read from the disk, we're talking about hard page fault. Processes that page get charged for a lot of CPU time, all of it in the kernel mode. If you have gtop (my kindest advice is to get it), you can set preferences and see kernel mode for the processes. Ones consuming large amounts of the kernel mode are ones that are paging. On 11/03/2003 01:24:27 PM, Sai Selvaganesan wrote: hi tanel and mladen not every time a process is started does it swap but sometimes swapping does happen.(this is from the top o/p which shows a increase in the memory used in swap.).how do we check whether a single process swaps or not? and the dbw process is using more % of memory than a couple of days back.(o/p pf ps aux). is this how linux kernel works or is there something else i can check. thanks sai what is meant by OP,tanel.. Tanel Poder [EMAIL PROTECTED] wrote: Thanks Mladen, that was a good tip about linux kernel enhancement, however OP still uses 2.4.9 as stated in original post. I just wanted to know whether OP actually sees excessive paging or just memory being full, the latter one, as you know, isn't really a problem. Tanel. - Original Message - To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 5:39 PM The whole thing comes as a consequence of using buffered I/O. New linux kernels (2.4.18 and later) have new memory management, which allows the kernel to grab more memory for buffers in periods of intense I./O activity. If you have a very active database on ReiserFS or Ext3, Linux is going to try to help you out by allocating more memory for the file system buffers, even by stealing pages from the active processes, which will, in turn. start paging. The only possible response is to eliminate the buffered I/ O and switch to non-buffered I/O. That is not so hard to do. On 2003.11.01 09:44, Tanel Poder wrote: Just for clarification, do you actually see swapping when starting a new process or you just guess linux would swap because you don't see free memory in top output? Tanel. - Original Message - From: Sai Selvaganesan To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 1:34 AM Subject: RE: memory usage by dbw very high rich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08) is used by non shared memory size. i went thru all the processes and found dbwr using the max %mem. what could be the reason? sai Jesse, Rich wrote: If I'm not mistaken, this figure includes the size of the shared memory segment from the SGA. Take the output of the oracle line of ipcs -a (hopefully you'll only have one!) and subtract it from the process size to get a better idea of the non-shared memory size of the process. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA -Original Message- Sent: Friday, October 31, 2003 3:49 PM To: Multiple recipients of list ORACLE-L hi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swapping when any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp o/p from top: 1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35 132 proces! ses: 131 sleeping, 1 running, 0 zombie, 0 stopped CPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idle CPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idle CPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idle CPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idle Mem: 3089964K av, 3083380K used, 6584K free, 846848K shrd, 193448K buff Swap: 2048152K av, 1652K used, 2046500K free 1852468K cached sga size: Total System Global Area
Re: memory usage by dbw very high
Thanks Mladen, that was a good tip about linux kernel enhancement, however OP still uses 2.4.9 as stated in original post. I just wanted to know whether OP actually sees excessive paging or just memory being full, the latter one, as you know, isn't really a problem. Tanel. - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Saturday, November 01, 2003 5:39 PM The whole thing comes as a consequence of using buffered I/O. New linux kernels (2.4.18 and later) have new memory management, which allows the kernel to grab more memory for buffers in periods of intense I./O activity. If you have a very active database on ReiserFS or Ext3, Linux is going to try to help you out by allocating more memory for the file system buffers, even by stealing pages from the active processes, which will, in turn. start paging. The only possible response is to eliminate the buffered I/ O and switch to non-buffered I/O. That is not so hard to do. On 2003.11.01 09:44, Tanel Poder wrote: Just for clarification, do you actually see swapping when starting a new process or you just guess linux would swap because you don't see free memory in top output? Tanel. - Original Message - From: Sai Selvaganesan To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 1:34 AM Subject: RE: memory usage by dbw very high rich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08) is used by non shared memory size. i went thru all the processes and found dbwr using the max %mem. what could be the reason? sai Jesse, Rich [EMAIL PROTECTED] wrote: If I'm not mistaken, this figure includes the size of the shared memory segment from the SGA. Take the output of the oracle line of ipcs -a (hopefully you'll only have one!) and subtract it from the process size to get a better idea of the non-shared memory size of the process. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA -Original Message- Sent: Friday, October 31, 2003 3:49 PM To: Multiple recipients of list ORACLE-L hi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swapping when any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp o/p from top: 1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35 132 proces! ses: 131 sleeping, 1 running, 0 zombie, 0 stopped CPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idle CPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idle CPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idle CPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idle Mem: 3089964K av, 3083380K used, 6584K free, 846848K shrd, 193448K buff Swap: 2048152K av, 1652K used, 2046500K free 1852468K cached sga size: Total System Global Area 1084823632 bytes Fixed Size 452688 bytes Variable Size 335544320 bytes Database Buffers 738197504 bytes Redo Buffers 10629120 bytes pga aggregate size:700M and ps o/p of dbw process USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND oracle 4062 0.0 16.4 1131260 508168 ? S 10:16 0:06 ora_dbw0_revenue please advise. what is really going on. thanks sai -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Mladen Gogala Oracle DBA -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Mladen Gogala INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing
Re: memory usage by dbw very high
Just for clarification, do you actually see swapping when starting a new process or you just guess linux would swap because you don't see "free" memory in top output? Tanel. - Original Message - From: Sai Selvaganesan To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 1:34 AM Subject: RE: memory usage by dbw very high rich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08)is used by non shared memory size. i went thru all the processes and found dbwr using the max %mem. what could be the reason? sai"Jesse, Rich" [EMAIL PROTECTED] wrote: If I'm not mistaken, this figure includes the size of the shared memorysegment from the SGA. Take the output of the "oracle" line of "ipcs -a"(hopefully you'll only have one!) and subtract it from the process size toget a better idea of the non-shared memory size of the process.RichRich Jesse System/Database Administrator[EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA-Original Message-Sent: Friday, October 31, 2003 3:49 PMTo: Multiple recipients of list ORACLE-Lhii have a system that has no active users at this point of time. the memoryused by the dbw process is very high leading to a lot of swapping when anyprocess starts.here are the spcesversion:9.2.0.4os:Linux 2.4.9-e.24smpo/p from top:1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35132 proces! ses: 131 sleeping, 1 running, 0 zombie, 0 stoppedCPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idleCPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idleCPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idleCPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idleMem: 3089964K av, 3083380K used, 6584K free, 846848K shrd, 193448KbuffSwap: 2048152K av, 1652K used, 2046500K free 1852468Kcachedsga size:Total System Global Area 1084823632 bytesFixed Size 452688 bytesVariable Size 335544320 bytesDatabase Buffers 738197504 bytesRedo Buffers 10629120 bytespga aggregate size:700Mand ps o/p of dbw processUSER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMANDoracle 4062 0.0 16.4 1131260 508168 ? S 10:16 0:06ora_dbw0_revenueplease advise. what is really going on.thankssai-- Please see the official ORACLE-L FAQ: http://www.orafaq.net-- Author: Jesse, RichINET: [EMAIL PROTECTED]Fat City Network Services -- 858-538-5051 http://www.fatcity.comSan Diego, California -- Mailing list and web hosting services-To REMOVE yourself from this mailing list, send an E-Mail messageto: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and inthe message BODY, include a line containing: UNSUB ORACLE-L(or the name of mailing list you want to be removed from). You mayalso send the HELP command for other information (like subscribing).
Re: memory usage by dbw very high
The whole thing comes as a consequence of using buffered I/O. New linux kernels (2.4.18 and later) have new memory management, which allows the kernel to grab more memory for buffers in periods of intense I./O activity. If you have a very active database on ReiserFS or Ext3, Linux is going to try to help you out by allocating more memory for the file system buffers, even by stealing pages from the active processes, which will, in turn. start paging. The only possible response is to eliminate the buffered I/ O and switch to non-buffered I/O. That is not so hard to do. On 2003.11.01 09:44, Tanel Poder wrote: Just for clarification, do you actually see swapping when starting a new process or you just guess linux would swap because you don't see free memory in top output? Tanel. - Original Message - From: Sai Selvaganesan To: Multiple recipients of list ORACLE-L Sent: Saturday, November 01, 2003 1:34 AM Subject: RE: memory usage by dbw very high rich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08) is used by non shared memory size. i went thru all the processes and found dbwr using the max %mem. what could be the reason? sai Jesse, Rich [EMAIL PROTECTED] wrote: If I'm not mistaken, this figure includes the size of the shared memory segment from the SGA. Take the output of the oracle line of ipcs -a (hopefully you'll only have one!) and subtract it from the process size to get a better idea of the non-shared memory size of the process. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA -Original Message- Sent: Friday, October 31, 2003 3:49 PM To: Multiple recipients of list ORACLE-L hi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swapping when any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp o/p from top: 1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35 132 proces! ses: 131 sleeping, 1 running, 0 zombie, 0 stopped CPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idle CPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idle CPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idle CPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idle Mem: 3089964K av, 3083380K used, 6584K free, 846848K shrd, 193448K buff Swap: 2048152K av, 1652K used, 2046500K free 1852468K cached sga size: Total System Global Area 1084823632 bytes Fixed Size 452688 bytes Variable Size 335544320 bytes Database Buffers 738197504 bytes Redo Buffers 10629120 bytes pga aggregate size:700M and ps o/p of dbw process USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND oracle 4062 0.0 16.4 1131260 508168 ? S 10:16 0:06 ora_dbw0_revenue please advise. what is really going on. thanks sai -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Mladen Gogala Oracle DBA -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Mladen Gogala INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
memory usage by dbw very high
hi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swapping when any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp o/p from top: 1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35132 processes: 131 sleeping, 1 running, 0 zombie, 0 stoppedCPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idleCPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idleCPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idleCPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idleMem: 3089964K av, 3083380K used, 6584K free, 846848K shrd, 193448K buffSwap: 2048152K av, 1652K used, 2046500K free 1852468K cached sga size: Total System Global Area 1084823632 bytesFixed Size 452688 bytesVariable Size 335544320 bytesDatabase Buffers 738197504 bytesRedo Buffers 10629120 bytes pga aggregate size:700M and ps o/p of dbw process USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND oracle 4062 0.0 16.4 1131260 508168 ? S 10:16 0:06 ora_dbw0_revenue please advise. what is really going on. thanks sai
RE: memory usage by dbw very high
If I'm not mistaken, this figure includes the size of the shared memory segment from the SGA. Take the output of the oracle line of ipcs -a (hopefully you'll only have one!) and subtract it from the process size to get a better idea of the non-shared memory size of the process. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA -Original Message- Sent: Friday, October 31, 2003 3:49 PM To: Multiple recipients of list ORACLE-L hi i have a system that has no active users at this point of time. the memory used by the dbw process is very high leading to a lot of swapping when any process starts. here are the spces version:9.2.0.4 os:Linux 2.4.9-e.24smp o/p from top: 1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35 132 processes: 131 sleeping, 1 running, 0 zombie, 0 stopped CPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idle CPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idle CPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idle CPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idle Mem: 3089964K av, 3083380K used,6584K free, 846848K shrd, 193448K buff Swap: 2048152K av,1652K used, 2046500K free 1852468K cached sga size: Total System Global Area 1084823632 bytes Fixed Size 452688 bytes Variable Size 335544320 bytes Database Buffers 738197504 bytes Redo Buffers 10629120 bytes pga aggregate size:700M and ps o/p of dbw process USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND oracle4062 0.0 16.4 1131260 508168 ?S10:16 0:06 ora_dbw0_revenue please advise. what is really going on. thanks sai -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: memory usage by dbw very high
rich the ipcs output shows 1.1 gb. so nearly 2 gb(total ram size is 3.08)is used by non shared memory size. i went thru all the processes and found dbwr using the max %mem. what could be the reason? sai"Jesse, Rich" [EMAIL PROTECTED] wrote: If I'm not mistaken, this figure includes the size of the shared memorysegment from the SGA. Take the output of the "oracle" line of "ipcs -a"(hopefully you'll only have one!) and subtract it from the process size toget a better idea of the non-shared memory size of the process.RichRich Jesse System/Database Administrator[EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA-Original Message-Sent: Friday, October 31, 2003 3:49 PMTo: Multiple recipients of list ORACLE-Lhii have a system that has no active users at this point of time. the memoryused by the dbw process is very high leading to a lot of swapping when anyprocess starts.here are the spcesversion:9.2.0.4os:Linux 2.4.9-e.24smpo/p from top:1:44pm up 29 days, 23:55, 4 users, load average: 1.73, 1.68, 1.35132 proces! ses: 131 sleeping, 1 running, 0 zombie, 0 stoppedCPU0 states: 24.4% user, 2.2% system, 0.0% nice, 72.2% idleCPU1 states: 0.5% user, 0.5% system, 0.0% nice, 98.0% idleCPU2 states: 0.0% user, 0.1% system, 0.0% nice, 99.4% idleCPU3 states: 0.3% user, 0.4% system, 0.0% nice, 98.3% idleMem: 3089964K av, 3083380K used, 6584K free, 846848K shrd, 193448KbuffSwap: 2048152K av, 1652K used, 2046500K free 1852468Kcachedsga size:Total System Global Area 1084823632 bytesFixed Size 452688 bytesVariable Size 335544320 bytesDatabase Buffers 738197504 bytesRedo Buffers 10629120 bytespga aggregate size:700Mand ps o/p of dbw processUSER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMANDoracle 4062 0.0 16.4 1131260 508168 ? S 10:16 0:06ora_dbw0_revenueplease advise. what is really going on.thankssai-- Please see the official ORACLE-L FAQ: http://www.orafaq.net-- Author: Jesse, RichINET: [EMAIL PROTECTED]Fat City Network Services -- 858-538-5051 http://www.fatcity.comSan Diego, California -- Mailing list and web hosting services-To REMOVE yourself from this mailing list, send an E-Mail messageto: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and inthe message BODY, include a line containing: UNSUB ORACLE-L(or the name of mailing list you want to be removed from). You mayalso send the HELP command for other information (like subscribing).
