Re: OT: cached memory
On Jun 13, 2012, at 5:02 PM, Dan Letkeman wrote: I understand the concept, as I have read many documents like that. I am more interested in a real world example of how much free memory for caching is recommended for an average server. Dan. It depends on many things, but what I'd do to find the optimum cache size is: (1) Start with some limit, say 128 MB. (2) Observe the server's performance over time, and memory usage. (3) Pick some reasonable time, like I want it to hit the max memory size in 3 days or one week (4) If it reaches the maximum too quickly, add more cache size. I suspect this is one metric that would help greatly to add to the XML stats... Cache hit rate is sort of a standard metric. --Michael ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
OT: cached memory
Hello, Just wondering if anyone has a real world example of how much cached memory a server really needs? If I run the command free -m it shows that it is using all of the memory on the server and most of it is cached. I understand the concept and the reasoning, but what I would like to know is how much is a reasonable amount to have? I am assuming that if I gave this server 10 times the amount it would eventually cache that as well. total used free sharedbuffers cached Mem: 3017 2961 56 0158 2434 -/+ buffers/cache:368 2649 Swap: 5023 0 5023 Thanks, Dan. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: OT: cached memory
this is a common source of confusion and more of a linuxism...it will fill all available memory with cache, and reclaim as needed. you can adjust it somewhat with various sysctls. http://www.linuxhowtos.org/System/Linux%20Memory%20Management.htm -Original Message- From: Dan Letkeman danletke...@gmail.com Date: Wednesday, June 13, 2012 10:50 AM To: bind-users bind-users@lists.isc.org Subject: OT: cached memory Hello, Just wondering if anyone has a real world example of how much cached memory a server really needs? If I run the command free -m it shows that it is using all of the memory on the server and most of it is cached. I understand the concept and the reasoning, but what I would like to know is how much is a reasonable amount to have? I am assuming that if I gave this server 10 times the amount it would eventually cache that as well. total used free sharedbuffers cached Mem: 3017 2961 56 0158 2434 -/+ buffers/cache:368 2649 Swap: 5023 0 5023 Thanks, Dan. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: OT: cached memory
I understand the concept, as I have read many documents like that. I am more interested in a real world example of how much free memory for caching is recommended for an average server. Dan. On Wed, Jun 13, 2012 at 1:00 PM, Mike Hoskins micho...@cisco.com wrote: this is a common source of confusion and more of a linuxism...it will fill all available memory with cache, and reclaim as needed. you can adjust it somewhat with various sysctls. http://www.linuxhowtos.org/System/Linux%20Memory%20Management.htm -Original Message- From: Dan Letkeman danletke...@gmail.com Date: Wednesday, June 13, 2012 10:50 AM To: bind-users bind-users@lists.isc.org Subject: OT: cached memory Hello, Just wondering if anyone has a real world example of how much cached memory a server really needs? If I run the command free -m it shows that it is using all of the memory on the server and most of it is cached. I understand the concept and the reasoning, but what I would like to know is how much is a reasonable amount to have? I am assuming that if I gave this server 10 times the amount it would eventually cache that as well. total used free shared buffers cached Mem: 3017 2961 56 0 158 2434 -/+ buffers/cache: 368 2649 Swap: 5023 0 5023 Thanks, Dan. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: OT: cached memory
On Jun 13, 2012, at 3:02 PM, Dan Letkeman wrote: I understand the concept, as I have read many documents like that. I am more interested in a real world example of how much free memory for caching is recommended for an average server. The OS likes to keep a few megabytes of prezeroed pages handy for emergency purposes, but otherwise, free memory is wasted memory. One can infer that more memory would help system performance if you are using more than a minor amount of swap, or if you see significant amounts of paging/swapping in vmstat or similar... Regards, -- -Chuck ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
