Re: [CentOS] centos 5.5 check memoray usage too high???
kernel is: 2.6.18-194.26.1.el5 #1 SMP Tue Nov 9 12:54:20 EST 2010 x86_64 x86_64 x86_64 GNU/Linux --- 11/2/3 (四)，Kwan Lowe kwan.l...@gmail.com 寫道： 寄件者: Kwan Lowe kwan.l...@gmail.com 主旨: Re: [CentOS] centos 5.5 check memoray usage too high??? 收件者: CentOS mailing list centos@centos.org 日期: 2011年2月3日,四,上午2:06 On Wed, Feb 2, 2011 at 4:58 PM, mcclnx mcc mcc...@yahoo.com.tw wrote: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. his server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. Since server have 128 GB RAM and only 1 application. 狢 really don't belive that. 痃oes there has some way can check memory utilitation ? What kernel are you using? Is your app 64-bit? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On Thu, 2011-02-03 at 20:18 +0800, mcclnx mcc wrote: kernel is: 2.6.18-194.26.1.el5 #1 SMP Tue Nov 9 12:54:20 EST 2010 x86_64 x86_64 x86_64 GNU/Linux I'm on Centos 5.5 and the kernel on my desktop machine is 2.6.18-194.32.1.el5 #1 SMP Wed Jan 5 17:52:25 EST 2011 x86_64 x86_64 x86_64 GNU/Linux -- With best regards, Paul. England, EU. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
Free is very good. $ free total used free sharedbuffers cached Mem: 131961872 131342464 619408 01062984 119627256 -/+ buffers/cache: 10652224 121309648 Swap:131074292 89220 130985072 --- 11/2/2 (三)，Sean Hart boardn...@blacklight.net 寫道： 寄件者: Sean Hart boardn...@blacklight.net 主旨: Re: [CentOS] centos 5.5 check memoray usage too high??? 收件者: centos@centos.org 日期: 2011年2月2日,三,下午4:59 On 2/2/11 1:58 PM, mcclnx mcc wrote: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. Since server have 128 GB RAM and only 1 application. I really don't belive that. Does there has some way can check memory utilitation ? What is the output of the command free? ~Sean ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
Mcclnx mcc wrote on Thu, 3 Feb 2011 23:20:10 +0800 (CST): Free is very good. and what does your monitoring tool show now? Nearly 100%? Kai ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On 2/3/2011 7:36 AM, Always Learning wrote: On Thu, 2011-02-03 at 20:18 +0800, mcclnx mcc wrote: kernel is: 2.6.18-194.26.1.el5 #1 SMP Tue Nov 9 12:54:20 EST 2010 x86_64 x86_64 x86_64 GNU/Linux I'm on Centos 5.5 and the kernel on my desktop machine is 2.6.18-194.32.1.el5 #1 SMP Wed Jan 5 17:52:25 EST 2011 x86_64 x86_64 x86_64 GNU/Linux If your swap drive is empty, as yours is, there is no shortage of ram. If your ram is full, as yours is, simply think of this as an automatic ram drive created and maintained by the system. You should be worried if ram is not full, unless your ram is greater than the total of everything accessed in the recent past. Basically, seeing your report is verification of 'perfection' with regards to efficiency (although I suppose the algorithm for what is stored could be argued until the end of days). Use of ram is fast... swap slow. Think windows rolling off to swap for a moment. John Hinton -- John Hinton 877-777-1407 ext 502 http://www.ew3d.com Comprehensive Online Solutions ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On Thu, Feb 3, 2011 at 7:18 AM, mcclnx mcc mcc...@yahoo.com.tw wrote: kernel is: 2.6.18-194.26.1.el5 #1 SMP Tue Nov 9 12:54:20 EST 2010 x86_64 x86_64 x86_64 GNU/Linux What sort of application? Is it 64-bit aware? What is the monitor checking? Also, there are some things to keep in mind if it's a Java-based application. You have to set heapsize differently (or at least, used to have to) on 32-bit vs 64-bit Java. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] centos 5.5 check memoray usage too high???
We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. Since server have 128 GB RAM and only 1 application. I really don't belive that. Does there has some way can check memory utilitation ? Thanks. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On 2/2/11 1:58 PM, mcclnx mcc wrote: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. Since server have 128 GB RAM and only 1 application. I really don't belive that. Does there has some way can check memory utilitation ? What is the output of the command free? ~Sean ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
on 2/2/2011 1:58 PM mcclnx mcc spake the following: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. Since server have 128 GB RAM and only 1 application. I really don't belive that. Does there has some way can check memory utilitation ? Thanks. Linux has a habit of using memory to store buffers and speed disk re-accesses. As soon as an application needs that memory, it will be flushed if dirty and released. Memory unused is memory not needed. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On Thu, Feb 03, 2011 at 05:58:19AM +0800, mcclnx mcc wrote: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. It sounds like your monitor tool is probably misconfigured and is looking at free memory, which is a very low value 'cos unused memory is used as disk cache. eg % free -m total used free sharedbuffers cached Mem: 3987 3551435 0330 2987 -/+ buffers/cache:233 3753 Swap: 2047 0 2047 This machine has 435M free, out of almost 4G. Except not really; it's got 3753M available for programs to use and is only using 233M of memory for real stuff! -- rgds Stephen ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
on 05:58 Thu 03 Feb, mcclnx mcc (mcc...@yahoo.com.tw) wrote: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. Since server have 128 GB RAM and only 1 application. I really don't belive that. Does there has some way can check memory utilitation ? Make sure your tool is reporting utilization less cache. As others have noted, the -/+ buffers/cache line in free output is what you're looking for. http://www.linuxatemyram.com/ If you've got sar (sysstat) installed and activated (read the manpage and /usr/share/doc/sysstat* materials if not), numerous system resource usages are logged every ten minutes. For memory usage: 'sar -r': 12:00:01 AM kbmemfree kbmemused %memused kbbuffers kbcached kbswpfree kbswpused %swpused kbswpcad 12:10:01 AM 45877732 3573788 7.23208792 1948316 2097144 0 0.00 0 12:20:01 AM 45875572 3575948 7.23208792 1948336 2097144 0 0.00 0 12:30:01 AM 45877120 3574400 7.23208796 1948352 2097144 0 0.00 0 12:40:01 AM 45878352 3573168 7.23208796 1948368 2097144 0 0.00 0 12:50:01 AM 45876080 3575440 7.23208800 1948384 2097144 0 0.00 0 01:00:01 AM 45877244 3574276 7.23208800 1948408 2097144 0 0.00 0 There are tools (NOT currently in CentOS) to graph/visualize these outputs as well. If you want per-process accounting, you can get that as well, but it'll cost you some performance overhead and a lot of set-up. -- Dr. Ed Morbius Chief Scientist Krell Power Systems Unlimited ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On 03/02/11 10:58, mcclnx mcc wrote: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. As previously mentioned, Linux operates on a memory full model, so caches and buffers need to accounted for. Is this monitor tool getting its data via SNMP? If so, you should be able to get the real amount of memory available using the formula memAvailReal + memBuffer + memCache (all of these can be found under UCD-SNMP-MIB::memory if you are using the NetSNMP agent.) $ snmpget -c public localhost UCD-SNMP-MIB::memCached.0 UCD-SNMP-MIB::memCached.0 = INTEGER: 169280 kB $ snmpget -c public localhost UCD-SNMP-MIB::memBuffer.0 UCD-SNMP-MIB::memBuffer.0 = INTEGER: 123400 kB $ snmpget -c public localhost UCD-SNMP-MIB::memAvailReal.0 UCD-SNMP-MIB::memAvailReal.0 = INTEGER: 26904 kB $ free -tk total used free sharedbuffers cached Mem:514512 487244 27268 0 123444 169344 -/+ buffers/cache: 194456 320056 Swap: 979956676 979280 Total: 1494468 4879201006548 Brief check: 26904 + 123400 + 169280 == 319584, which is near enough to 320056 (given that I ran the commands above with a bit of a pause in between) However, as a practical aside, looking at the amount of memory used is not particularly useful for determining if a host has too little. If that is what is wanted, it would be better to monitor the number of pages swapped in/out. (ie. what the 'vmstat' tool reports). If monitoring using SNMP, and the NetSNMP agent is being used, you can get this in the UCD-SNMP-MIB::ssSwapIn and ssSwapOut variables, which report amount of memory swapped in/out in the last minute (in SNMP terms, this is a gauge), or ssRawSwapIn and ssRawSwapOut if you want pages instead (which is a counter, and thus more useful). Hope it helps, Cameron ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On Wed, Feb 2, 2011 at 4:58 PM, mcclnx mcc mcc...@yahoo.com.tw wrote: We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This server only have one application running and few people use it. Every week I ata least get one or two messages from monitor tool mail to me say: Message=Memory Utilization is 92.02%, crossed warning (80) or critical (90) threshold. Since server have 128 GB RAM and only 1 application. I really don't belive that. Does there has some way can check memory utilitation ? What kernel are you using? Is your app 64-bit? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] centos 5.5 check memoray usage too high???
On 02/02/11 1:58 PM, mcclnx mcc wrote: Since server have 128 GB RAM and only 1 application. I really don't belive that. Does there has some way can check memory utilitation ? while your app is running, $ top as everyone has said, remember to add the 'cached' and 'buffered' to the 'free' to find out whats actually potentially available. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
