1
vote
1answer
41 views

What happens to a random bit error in the cache on an Intel CPU?

I have a system with ECC RAM and a Xeon E3 CPU. My understanding is that ECC circuits on the RAM will detect corruption from random bit errors in the RAM chips. But what happens to random bit errors ...
2
votes
2answers
58 views

Memory used by unknown processes on OEL6 - without cache and slabcache

I've searched through "Where is my Linux memory?" questions, but I couldn't find a similar scenario for my kind of leak: OEL 6.3 x86_64 Linux with 6GB of RAM without any of my main components ...
3
votes
1answer
152 views

Growing OS cache in RAM causing high system CPU usage

Long question, so please bare with me: I'm having a weird issue with a server that I've never seen before. On a machine with ~30G of RAM with an application that takes ~10G (spread across hundreds of ...
49
votes
10answers
6k views

Why drop caches in Linux?

In our servers we have a habit of dropping caches at midnight. sync; echo 3 > /proc/sys/vm/drop_caches When I run the code it seems to free up lots of RAM, but do I really need to do that. ...
2
votes
2answers
180 views

Memory mapping files for a blazing fast webserver on Linux

Is there any simple way of telling Linux to keep a directory of files cached in memory? I realized that Node.Js and Apache are spending most time on file I/O, making users wait if you have a lot of ...
0
votes
1answer
314 views

Linux empty buffer cache command permission denied

I'm using the following commands to flush cache: # sync; echo 3 > /proc/sys/vm/drop_caches # sync; echo 2 > /proc/sys/vm/drop_caches # sync; echo 1 > /proc/sys/vm/drop_caches When I use ...
0
votes
1answer
181 views

How to find L1, L1i, L1d cache from dmidecode output?

How to find L1 , L1d, L1i cache from dmidecode output ? (NOTE: dmidecode file is from different server for which I do not have access, So I can not run lscpu command to find the same) ...
3
votes
4answers
2k views

Slow Memcached: Average 10ms memcached `get`

We're using Newrelic to measure our Python/Django application performance. Newrelic is reporting that across our system "Memcached" is taking an average of 12ms to respond to commands. Drilling down ...
0
votes
2answers
85 views

Has L2 cache stopped getting faster? [closed]

I was reading this question which references L2 cache hits as taking about 10ns: Are networks now faster than disks? However I distinctly remember there being 10ns cache ICs for the 486 generation. A ...
1
vote
3answers
224 views

Is it safe to use up all memory on linux server, not leaving anything for the cache?

I have a CentOS server fully dedicated to MySQL 5.5 (with innodb tables mostly). Server has 32 GB RAM, SSD disks, and avarage memory usage looks like this: So about 25GB is in use and about 6.5GB ...
3
votes
2answers
3k views

Linux cached memory: Over 85% of cached memory and using swap

I read about Linux and cachd memory at linuxatemyram but there is something that doesn't make sense to me, if the server have even a low load, instead of freeing some cached memory it starts using ...
1
vote
1answer
1k views

Centos is using all memory for cache and not giving it up

total used free shared buffers cached Mem: 1024 1020 3 0 0 859 -/+ buffers/cache: 160 863 With 863 ...
-1
votes
2answers
531 views

Concerning memory usage statistics on debian squeeze

So I have a server, and I'm being reported different/strage memory from several locations and I'm having trouble understanding what it all means. Take this for example: root@****:~# free -m ...
-1
votes
1answer
182 views

Cache Total Entries increase and decrease as a delta shape. Why?

My performance counter "cache total entries" "cache total hits" "cache total misses" keeps increasing and decreasing as a delta shape around every 1 hour.The decreasing is much fast than increasing. ...
6
votes
5answers
2k views

Free / Cached / Available memory on Linux

I have read that linux uses free memory for caching, to make system faster. However, both Nagios and Paessler PRTG monitoring system show me that my memory usage is critical. I could change Nagios ...
-2
votes
1answer
814 views

How do i restart my linux server in every 2 days via crontab? [duplicate]

I have a Linux server containing the os version below: Linux 2.6.32-220.7.1.el6.x86_64 I want to restart it in every 2 days, please help me, I want to do it via crontab. Another help, I used a ...
1
vote
1answer
321 views

Debian (wheezy) force cache to RAM

I have Linux server running about 6 game servers. I have 3 GB total of RAM but I use only about 500 MB. Is there a way to cache one of my game servers (all the files - even not actually used maps etc. ...
-1
votes
1answer
298 views

Running < 20 classic asp sites on 2008 IIS7. Memory use brings the server to its knees

I am hosting < 20 asp classic websites on a Windows 2008 Server. All of the websites run on my custom CMS. I am migrating them from a 2003 server. Memory was also an issue when these sites were ...
0
votes
0answers
311 views

Apache CentOS taking up too much (cache?) memory

The server has physical memory of 4gb. We have a desktop CentOS (5.) running a VM (virtualbox) as the server. The VM is allowed 1.8gb memory (as per VirtualBox recommendation). My problem is that ...
3
votes
2answers
872 views

Unexplained cache RAM drops on Linux machine

I run a CentOS 5.7 64 machine with 24gb ram and running kernel 2.6.18-274.12.1.el5. This machine runs only Nginx, php-fpm and Xcache as extra applications. Since about 3 weeks my memory behavior on ...
1
vote
2answers
2k views

MySQL consuming nearly all memory in cache? [duplicate]

I am running a server with 24G of RAM. The only thing running here is a MySQL server configured as Master. When I check the memory via free -m I am getting this: total used ...
2
votes
0answers
838 views

How to measure dcachesize usage (and reduce it)

I have a VPS running CentOS 5.7 (Final), 32-bit. Right after boot, when I run # cat /proc/user_beancounters I see that my dcachesize usage is at about 4100000, while my VPS is set up with a limit of ...
1
vote
2answers
343 views

How can I tell if files are being read from disk cache?

I have two processes that peform differently on two boxes that are identical except for the amount of ram. One box has 32GB and the other has 16GB and the process performs significantly better on the ...
1
vote
0answers
191 views

Tracking huge buffer usage under Linux

I'v a Linux server running under Debian Lenny with 4Go of RAM. It doesn't run a large number of stuffs: Postfix/spamassassin (daemon mode) Bind9 KVM (one guest - 1Go of RAM for it) Every day at ...
1
vote
1answer
692 views

Increase memory to memcached

I need to increase the memory size for memcached. I have done this before, but I cannot remember all the steps that I took. If I remember correctly, I downloaded /etc/sysconfig/memcached and changed ...
0
votes
2answers
82 views

Why would two load-balanced systems differ so greatly in cached memory?

We have a java application running on two RHEL5.5 systems. We recently got into a situation where we needed to add more memory for both systems. Each system was rebooted within 5 minutes of each ...
0
votes
3answers
162 views

Filesystem cache accessible via HTTP?

After searching the web for hours and couldn't find what I was looking for, I thought someone here might have an idea ;-) I'm looking for Linux a program that will cache in memory a designated ...
1
vote
1answer
692 views

VMware RHEL5 guest OS cached memory release

From everything I have read, RHEL will use all available/unused RAM for caching to increase performance. However, this becomes an issue for me in a VMware environment. VMware (ESX4) looks for guest ...
1
vote
3answers
476 views

Is it possible to build a cheap memcached server?

Is it possible to build a cheap memcached server?
13
votes
1answer
4k views

deleting linux cached ram [duplicate]

I have a webserver that has 8GB of ram and is running a pretty intensive php site (1 site) that does file manipulation, graphing, emailing, forums, you name it. The environment is far from static ...
0
votes
1answer
726 views

Is my centOS dedicated server caching disk files appropriately, or not?

Here's the head of the top output from my centOS 5 server, at a moment with very low load. What I want to know is whether it is using its free memory wisely to cache files from disk. Of 2G of RAM, ...
0
votes
2answers
720 views

Explanation for Linux cache shrinking?

We have a Linux server for which Cacti's memory usage graph reports decreasing cache size until the server eventually runs out of memory. Free memory remains low throughout, which is normal for Linux. ...
3
votes
2answers
925 views

Can you Utilize Server RAM for NAS Cache?

I have a 4 CPU 16GB RAM system with an Areca 1230 RAID card and 6 HDs in a RAID 0+1 configuration with 1 hot spare. System has 2 onboard 1Gpbs nics I want to turn the system into a NAS. It seems ...
0
votes
4answers
2k views

Turbo Memory Cache - Worth it for Laptops? [closed]

I am buying a new laptop (big fan of Lenovo, so will probably stick with it), and see an option that for about $40 I can add a 2GB Intel® Turbo Memory hard drive cache. I am wondering whether it's ...
12
votes
7answers
4k views

SQL Server - Force DB in memory?

We have a beefy Windows 2008 x64 server (4 x 4 core CPU, 32GB RAM) running SQL Server 2005 64-bit. We have a small (6GB) but very important database that is somewhat slow to access until the pages are ...