Tagged Questions

Synonym for: RAM - Acronym for: Random Access Memory, a type of computer data storage.

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1answer
78 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 ...
1
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2answers
154 views

Traffic increase causes VPS to crash due to RAM utilisation

I have a VPS which runs multiple Opencart sites and for the most part performs the task very well. Spec: CPU GenuineIntel, Intel(R) Xeon(R) CPU E5-2665 0 @ 2.40GHz Version Parallels Plesk Panel ...
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2answers
93 views

plenty of ram but still swapping

this is graph of my server ram you can see in graph that every time I restart mysqld, swap becomes zero. But increases over time. If i put innodb buffer pool in large size swap rises faster and if I ...
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2answers
120 views

vSwap vs Burstable RAM for OpenVZ

What is the big difference between vSwap and Burstable RAM? Does vSwap create and cause I/O by using disk? I know SWAP will use the disk so is vSwap the same as swap just virtualized in the ...
2
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2answers
185 views

How to free linux memory safely to improve server performance

We have a linux virtual server hosted through GoDaddy, and our site has been running slow recently. I poked around the server a bit (I am not a sysadmin and have very limited experience with linux, ...
13
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2answers
973 views

What RAM options do I need to know before buying Server RAM?

This is a proposed Canonical Question about Server Memory. I have to buy a Dell R420 server and there are various combinations (1600 and 1333 MHz RDIMMS and UDIMMS) and Performance Optimized vs. ...
2
votes
1answer
126 views

(VMware) Will a Linux guest VM swap when RAM usage is high even though Active is not?

We are currently having a discussion in my environment. The assumptions are that “The tools that are designed for a physical infrastructure memory management in Linux such as top, free, vmstat, ...
2
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2answers
97 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 ...
1
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1answer
149 views

Out of memory kill on Centos 6

For the last few days I am having regular out of memory problems on my Centos 6 server. Aug 1 03:40:42 myserver xinetd[2304]: START: smtp pid=11222 from=87.109.36.82 Aug 1 03:40:46 myserver ...
0
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1answer
61 views

Apache2 using up all my memory and stalling my wordpress instance (mysql)

Environment Ubuntu 12.04 / 1GB RAM / 40GB DISK / 1 CPU (RACKSPACE) Wordpress 3.9 mysql Ver 14.14 Distrib 5.5.38, for debian-linux-gnu (x86_64) using readline 6.2 Apache2 mod_php5 mod_rewrite When ...
3
votes
1answer
254 views

Where did my memory go on linux (no cache/slab/shm/ipcs)

This is a headless server with 8GB RAM (kernel 3.12)... even after only a few days, i get low on memory. in fact, this server has OOMed a few days ago... something is losing memory, but i don't know ...
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1answer
192 views

Redis server Memory Increased to 22GB and Crashed (OOM)

A redis server v2.8.4 is running on a Ubuntu 14.04 VPS with 8 GB RAM and 16 GB swap space (on SSDs). However htop shows that redis alone is taking up 22.4 G of memory! I do not think the redis ...
2
votes
2answers
75 views

Lots of major page faults in CentOS

We have a fairly complicated PHP script that's generating a lot of minor and major page faults. $> ps -o min_flt,maj_flt,time,cmd,pid 4686 MINFL MAJFL TIME CMD ...
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2answers
162 views

PHP eats up all the memory

Since this morning one of our webserver's memory getting filled up by php which eventually going to cause the server to start swapping, slow down and become unavailable (an ssh login takes like 5 ...
0
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1answer
71 views

Is memtester a good command line memory test?

I have spent awhile looking for a memory testing tool that works from the command line, and have been unable to find anything besides memtester (http://pyropus.ca/software/memtester/). Eventually ...
2
votes
3answers
577 views

How to increase swap space on a live server

On Ubuntu 14.04, the swap file has to be increased as the memory and swap usage are reaching 100% usage. On a live production server, can the swap be increased with minimal disruption to the service? ...
0
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1answer
108 views

Interpreting ipmitool ser list memory errors

I'm purchasing some second hand servers, which the seller has given me remote access to. Running ipmitool [..] ser list, they seem clean other than these repeated a few months ago on each: [..] | ...
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0answers
89 views

What is using all of my memory on Ubuntu 12.04?

I keep getting alarms from Rackspace telling me that my memory usage is too high, but I can't seem to find the culprit. I ran top SHIFT + M to see top output sorted by memory, and this is what I get ...
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1answer
42 views

Windows Server 2012 - What type of memory do I have? [duplicate]

My Windows Server is running on 3gb of memory right now, and I would like to upgrade to 16gb. However, I don't know what type of memory to buy. I know that the notches in the physical RAM are ...
4
votes
1answer
392 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 ...
2
votes
1answer
124 views

Cisco 7604 router runs out of memory when loading the IOS image, yet runs a different image with similar reqs

I am experiencing an unusual memory issue with a Cisco 7604 router, specifically the memory on the Supervisor Engine (SUP32-GE-3B) and how it pertains to IOS requirements. I was preparing the router ...
2
votes
2answers
529 views

HP Proliant DL360 G7 All DIMM indicator lights amber

I am currently doing a RAM upgrade on an HP proliant DL360 G7 server. After installing the new RAM (18x 8GB KTH-PL316E/8G) the LED indicator lights for every single DIMM turned amber and the health ...
2
votes
1answer
81 views

Startup Memory in Hyper-V dynamic Memory for IIS 7.5

I recently setup a 2012 server core with hyper-v. I then installed server core 2008 R2 as a client. Installed IIS and started hosting an internal website. I started running throughput tests and found ...
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0answers
100 views

PowerEdge R210 Memory Upgrade

I have a Dell PowerEdge R210 II running with 2GB of memory. I wanted to upgrade the memory to 10GB as I am running ESXi on the machine. I purchased an ECC RAM (2 x 4GB) which allows me to get the RAM ...
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0answers
784 views

Tomcat Memory - Setting in setenv.sh not respected

I have Tomcat 7.0.35 on CentOS. I have configured setenv.sh to have the following: export JAVA_OPTS="-Dfile.encoding=UTF-8 -Xms128m -Xmx1024m -XX:PermSize=256m -XX:MaxPermSize=512m" However under ...
0
votes
1answer
53 views

How can we calculate a processes' contribution to “commit” (/proc/meminfo “Committed_AS”)

We are seeing a "leak" in "commit" over time, and need to track the offending process(es). RSS ("used" memory") isn't leaking, but the commit is, and its causing the kernel to behave very cruelly ...
0
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0answers
60 views

lxc - java out of memory issues

I have a set of virtual machines on lxc container that run Ubuntu 14.04. All share same host and some of them are currently experiencing problems with java. Running java -version throws OutOfMemmory ...
2
votes
1answer
81 views

centos + php leak memory, but where?

I have a big php cronjob that run every 20minutes. After each execution the RAM memory used by the virtual server increase and not properly free once the script is terminated! But why? The memory ...
1
vote
1answer
148 views

CentOS only detecting 50% of ram on IBM Server

I have IBM server with 16 GB RAM installed. Initially it showed 16 GB with free | grep Mem | awk '{print $2}' but now it shows only 8116136 but it must show 16439208 When I do dmidecode ...
8
votes
1answer
2k views

How does vm.overcommit_memory work?

When I use the default settings: vm.overcommit_memory = 0 vm.overcommit_ratio = 50 I can read these values from /proc/meminfo file: CommitLimit: 2609604 kB Committed_AS: 1579976 kB But ...
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0answers
31 views

xen: domu require more memory than mem-set size

Assume that we have install two guest os in xen, named dom1 and dom2. Now, I start the dom1 and dom2, and both are configured with max-mem=4096M; note that my physical memory is 16GB. While dom1 and ...
3
votes
0answers
98 views

Unusually high nfs_inode_cache

My server is experiencing a high usage of nfs_inode_cache = 11G , im trying to figure out what's consuming all this , i know already that directories with large numbers of entries and deep directory ...
0
votes
2answers
112 views

Unexplained high memory usage [duplicate]

My server started being unable to spawn PHP instances to respond to HTTP requests as there wasn't enough available RAM. Free -m shows a reasonable amount left, but top and PS don't seem to be able to ...
1
vote
1answer
880 views

Dell R610 memory configuration for all 12 slots

I purchased 12 sticks of RAM on eBay to go into a Dell R610 server. The RAM is ECC REG PC3-12800 DDR3-1600 yet when I occupy all 12 slots with this ram I get the following error on boot: MEMORY ...
0
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0answers
39 views

Why does oracle vbox virtual memory differ when VMs do the same thing and are clones of each other?

I am running a large box with 11 instances of 64-bit Ubuntu 14. MemTotal: 50 Gb CPUs: 8 CPUs are pretty much 100% all day long. Memory is at about 60%. Swap not getting hit. Little bewildered by ...
0
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1answer
89 views

lvresize: command not found - RedHat

No search results on google for this. So i am really confused now. I am trying to increase the swap space and lvresize says command not found. Please Help !! using RedHat 64bit
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votes
1answer
54 views

TCP Server Memory management: #Connections Vs. #Requests

Given that, there is no theoretical limit to number of concurrent TCP connections a Windows 2008 server can handle. Only thing will happen is, with each connection there will be memory consumption in ...
2
votes
3answers
697 views

Mysql crashing, oom-killer, out of memory, tuning issues?

I just moved all of my websites to a new server with 4GB RAM. Almost immediately, mysql started crashing, and at one point, didn't reboot which caused a major outage (since I didn't notice until ...
1
vote
1answer
119 views

Loading a big database dump into PostgreSQL using cat

I have a pair of very large (~17 GB) database dumps that I want to load into postgresql 9.3. After installing the database packages, learning more or less how to use them, and fiddling around a little ...
0
votes
0answers
26 views

False flag multibit errors on highest populated DIMM socket on second CPU of Sunfire x2200. Faulty CPU or faulty motherboard?

I'm testing 2GB ECC Registered DIMMs in a Sunfire x2200. Recently the system event log (SEL) began logging Multibit Errors on the highest populated DIMM socket on CPU1. With 8 DIMMs on CPU1, the SEL ...
3
votes
1answer
298 views

In a HP server, can low voltage DIMMS and standard voltage DIMMs be mixed?

We are adding RAM to a HP Proliant DL380 G7 and were shipped standard voltage DIMMS. We have pre-installed some low voltage DIMMS. Is it acceptable to mix DIMM voltage in general? Is it advised? A ...
51
votes
10answers
8k 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. ...
4
votes
1answer
320 views

Linux page cache slows down IO on dual cpu server with 64GB ram

I have a massive problem with the linux page cache which slows down the IO. For instance if I copy a lvm partition with dd, linux cache the data in the buffers or caches (free –m). That is not the ...
1
vote
2answers
154 views

Solr 4.5 uses too much memory on consequent queries, GC runs causing timeouts

There is a index on Solr 4.5 which contains ~50K documents taking ~4Gb on disk. Physical RAM available to JVM is 6Gb (out of total 10Gb on server), OS is 64bit CentOS 5. One of the applications ...
0
votes
1answer
176 views

ECC CE (Correctable Error) occuring every 5 minutes exactly

On one of our computing nodes I am getting ECC CE (correctable errors). What is a little bit peculiar about is is that errors are not massive, just a single occurrence exactly every 5 minutes. ...
0
votes
1answer
319 views

Docker memory leak?

I'm running Docker 0.9.0 uname -a Linux 3.11.0-18-generic #32-Ubuntu SMP Tue Feb 18 21:11:14 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux I have 40 containers running at once. Each container is fairly ...
0
votes
1answer
83 views

yum update MemoryError 1G memory free

I am trying to do yum update and getting "MemoryError". The server (OpenVZ box) has 2G RAM and Percona MySQL server running with 1G InnoDB buffer configured. The OS is CentOS 6.5, kernel ...
2
votes
2answers
364 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
40 views

Is it possible to make KVR800D2D4P6 memory work on Intel DQ45CB

We have a self-made Intel DQ45CB based server/workstation in a server case in a datacenter. The system works just fine for it's purposes, but would do perfectly with a small memory upgrade. I've ...
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votes
2answers
999 views

Can EC2 instances dynamically add RAM while running?

This would help contribute to 0 downtime for me if possible. As far as I know it is not possible, but wanted to be sure.