Questions tagged [memory]
Synonym for: RAM - Acronym for: Random Access Memory, a type of computer data storage.
324
questions with no upvoted or accepted answers
9
votes
2
answers
2k
views
1GB VPS - Apache Worker MPM - FCGID - Max concurrent connections - RAM CAP
I have spent a week or two researching and setting up my server to run Apache with the Worker MPM and FCID. I am trying to optimize it to allow for the most concurrent connections possible. It has ...
- 89
8
votes
1
answer
4k
views
linux guarantee or reserve memory for a specific process
Is there a way to reserve a specific amount of memory for a specific service/process?
I would like to guarantee that OpenSSH always has enough memory available to it that it can accept a new SSH ...
- 1,189
5
votes
1
answer
539
views
How much physical RAM is "lost" to BIOS/UEFI?
Browsing the linux kernel output dmesg on 6 different systems (4 server, and for the sake of comparison also 2 laptops) I am shocked by the large amount of BIOS/UEFI reserved RAM
Three servers systems ...
- 171
5
votes
0
answers
1k
views
Node.js Server with PM2 Crashing with error ENOMEM - but no memory leak
I have an EC2 instance running a node.js server (Express based).
After deploying in a new environment, my service had started crashing almost instantly with spawn ENOMEM Errors like this one:
...
- 151
5
votes
1
answer
2k
views
Process Managment memory-leak in Windows Server x64?
After clean install and boot of OS Windows x64 I launched cmd.exe (any other exe) and closed it. Then I launch rammap.exe (http://technet.microsoft.com/en-us/sysinternals/ff700229.aspx). On the 2nd ...
- 71
4
votes
0
answers
446
views
Finding mystery Linux memory usage - not caches or slab (or ballooning?)
I have a Xen VM running Debian Linux with a weirdly large amount of RAM used. What might be the culprit? I believe I've ruled out the usual suspects of disk caching, kernel slab usage, and memory ...
- 3,106
4
votes
1
answer
6k
views
MariaDB using much more memory than it should
We are using MariaDB 10.3.32 on a Ubuntu 20.04.4 machine with 6 GB of memory, about 20 applications running on it. Databases are all InnoDB.
Even with mostly default settings (see on the bottom), ...
- 41
4
votes
1
answer
753
views
Apache is not using SWAP and it's reporting page allocation failure
Check the logs:
httpd: page allocation failure. order:4, mode:0xd0
Call Trace:
[<ffffffff8000f696>] __alloc_pages+0x2ef/0x308
[<ffffffff80017a40>] cache_grow+0x139/0x3c7
[<...
- 568
3
votes
2
answers
4k
views
php-fpm: why do I have a process memory usage higher than memory_limit
I know that there are a lot of related subjects, but I did not found my answer.
I have a dedicated server with 32Go of RAM (but I want php-fpm to use only 12Go max), and I have a php-fpm (7.2.13) ...
- 31
3
votes
0
answers
1k
views
how to find which memory stick error
There is a Inspur SA5212SC server involve memory error. In dmesg output I got some error:
{16}[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 1
{16}[Hardware Error]: APEI ...
- 31
3
votes
0
answers
426
views
Can esxi hot add memory using vim-cmd?
I've got HotAdd set to true and a bit less memory than I wanted allocated to a VM. I've got this in the vmx file:
memsize = "192"
mem.hotadd = "TRUE"
But, I've cut out my legs ...
- 2,208
3
votes
2
answers
4k
views
Slab reclaimable memory is not freed when needed
Correct me if I am wrong, but to my understanding slab reclaimable holds cached kernel objects which can be freed if needed. So if application needs to allocate more space, even if the 'free' memory ...
- 161
3
votes
1
answer
3k
views
EDAC memory error after upgrade server SuperMicro with CentOS 7. Is these specific errors of motherboard, OS or broken RAM module?
I have server on SuperMicro MBD-X9DRD-EF motherboard. It worked well at CentOS7 during the year with one CPU (Intel Original Xeon X6 E5-2620v2) and 128 Gb (8x16 Gb) LVDDR (1600MHz Crucial ECC Reg RTL (...
3
votes
0
answers
66
views
After move SQL isn't releasing memory for queries
We recently made a move from one VM hosting environment to another. The machine we moved is a clone so all settings are identical pre- and post-move. However in our new environment our SQL server is ...
- 457
3
votes
0
answers
361
views
BUG message on xenserver 6.5 - bad memory?
Several times a day I receive the following error in /var/log/messages. The server hangs and requires a reboot to respond again:
Feb 1 13:44:54 xenserver-abfuqvrs kernel: [35023.166776] BUG: unable ...
- 58
3
votes
0
answers
831
views
Why can't I malloc as much memory as `free` reports as being free?
The following C program allocates slices of 10MB of memory until it is killed by the Out of Memory killer.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <...
- 191
3
votes
2
answers
1k
views
Dell R900 memory bank mismatch
We've got two Dell R900 servers deployed in a well known managed hosting provider in the US. One of the Dell R900 servers has had its 128 GB memory (32x 4 GB) swapped out 6 times now. Every time the ...
- 194
3
votes
1
answer
2k
views
Avoiding memory full -> swap full -> crash
I'm experiencing an issue when sometimes the memory gets 100% full, and the swap file also, and the server becomes non-responsive and has to be restarted (causing also problems in database). This is ...
- 129
2
votes
0
answers
508
views
apache httpd using a lot of RAM memory and producing spikes in short time intervals
I have a problem with one of my servers.
Web server works well in 'normal' time period but one or two times per day there are spikes in RAM memory usage.
I put the Zabbix monitoring tool there, and ...
- 21
2
votes
0
answers
591
views
Can't track memory usage of MySQL docker container
I have a MySQL instance as a docker container managed by Hashicorp Nomad on an AWS EC2 t4g.small instance.
I need to monitor MySQL's memory usage because I have experienced OOM kills after ...
- 21
2
votes
0
answers
188
views
Why solaris doesn't see all the DIMMS installed?
This is a SPARC T4-2 Server. It has installed 128GB memory in 16 DIMMS 8GB each.
The prtdiag -v output shows
======================= Physical Memory Configuration ========================
Segment ...
2
votes
0
answers
597
views
VMware Cross-NUMA Performance penalty
I've been experiencing random unexpected slow-downs of a virtual SQL Server that I can't attribute to workload, storage or CPU (in fact it continued after the host was evacuated of other VMs).
I ...
- 21
2
votes
0
answers
268
views
Limit memory usage of an application with multiple instances
I got a program installed in 3 different machines, pointing to the same database, running at the same time. They are responsible for reading a huge file, process everything and then save on database.
...
- 29
2
votes
1
answer
2k
views
changing /proc/sys/vm/overcommit_memory broke my server
After changing it to 2 it closed my sftp session, and I cannot connect via ssh or sftp although it kept my session open. Whenever I run a command that isnt cd, I get -bash: fork: Cannot allocate ...
2
votes
0
answers
49
views
Differing "free memory" interpretation on virtualized vs. bare-metal Debian 9
I have the same software suite with roughly similarly sized datasets on two Debian 9 systems, with one big difference: os-1 runs on bare-metal and has better hardware, while os-2 is virtualized ...
- 135
2
votes
0
answers
87
views
Will More vCPU's and RAM Help Protect Against Some Smaller Scale DDoS Attacks?
Obviously having more vCPU's (virtual CPU's) and more RAM by them self won't be able to alone help stop and/or prevent a DDoS attack, but let's say after a DDoS attack is finished and/or slowing down ...
- 21
2
votes
1
answer
6k
views
AWS High Memory Usage. How to detect the cause?
I'm using Amazon EC2 instance t2.small. And the memory usage is always increasing up to > 90% usage.
Memory usage > 90 %
$ free -m
total used free shared buffers ...
- 121
2
votes
0
answers
227
views
Bad performance on better hardware
I have postgresql streaming replication on 2 hosts and I've faced with the problem of different performance compared between two servers. It looks like all sql queries on one host are slower on 70-90% ...
- 243
2
votes
0
answers
830
views
Frequent page allocation failures on a KVM
Lately my server has been going down quite often. It happens almost every day early in the morning.
Looking at the syslog, I found a lot of these:
Oct 11 06:51:12 pleskvm kernel: [1895007.359087] ...
- 125
2
votes
1
answer
479
views
Unexpected memory usage after SSL on Apache
We recently converted our web site to https. After certificate installation and testing we created a 301 redirect in .htaccess. Things went fine for a few days with little apparent performance ...
- 133
2
votes
0
answers
2k
views
How to test RAM on embedded ARM system? (Linux, no console)
I get a lot of memory dumps in dmesg, It seems to me every time the OS is trying to use any more than about 100 MB of RAM weird things are happening.
How can I test RAM on ARM, on running Linux ...
- 890
2
votes
2
answers
649
views
Active process swapping despite free memory
For some reason our system starts swapping (actively used memory) at around 60GB used memory. (see edit below, it seems I/O and disk cache usage, even of previously run processes has an effect)
...
- 121
2
votes
1
answer
778
views
Calculation of Xeon server memory bandwidth
I am looking at a dual socket server based on the Intel(R) Xeon(R) CPU E5-2640 v3 @ 2.60GHz
The configuration looks like this.
4 memory channels per socket
DIMMs are 8x32 GB DDR4 2133/1866 modules ...
- 21
2
votes
0
answers
88
views
LSF nodes die after exhausting all memory
I have a LSF cluster and experience the following problems.
After some time, random OS processes start to die (they become zombies or defunct), and the LSF nodes do not report any troubles back to ...
- 121
2
votes
0
answers
774
views
RHEL 6.7 cache causing out of memory errors
I have a (large) system that has cache behavior that I don't understand. It seems that the cache ran the system out of memory. How is this possible? Doesn't the kernel clean up the cache when there'...
- 31
2
votes
2
answers
61
views
Application Running as multiple processes
I have a java/tomcat application running on RedHat linux. Initially when I start the application, everything seems to be working perfectly fine. However, after some time, I guess 1-2 days, I witness ...
- 21
2
votes
2
answers
1k
views
Tomcat shuts down unexpectidly
I am using Apache Tomcat 8.0.23 with 1 GB RAM on centos 6 OS . I have used servlet and jsp for server side . But after few days it shuts down automatically . I have given memory size as CATALINA_OPTS="...
- 129
2
votes
0
answers
2k
views
Limit amount of allocateable memory for process
I've got a windows service written in C#, that does some heavy work (irrelevant for the question) running on a remote machine (Windows Server 2008).
Every now an then a client application contacts ...
2
votes
1
answer
152
views
What memory settings aside from page file size are significant for debugging performance issues on Windows Server 2008
While debugging a problem with slow hg cloning from Windows clients, I found that hg clone performance could be significantly improved (10x faster) on EC2 2012 virtual instances by reducing the ...
- 322
2
votes
0
answers
1k
views
Windows equivalent of Linux vmstat pswpin and pgfault?
Is there a way to query Windows for the total number of pages swaped in / out and total amount of page faults? (values found in /proc/vmstat on Linux)
I could only find ...
- 121
2
votes
0
answers
195
views
Xorg in an embedded system--leaking memory?
I'm working on an embedded system that runs a custom Linux platform and it appears that the Xorg process is leaking memory. According to top, Xorg's virtual memory grows until the system crashes. ...
2
votes
1
answer
570
views
Possible reasons for extremely low RAM usage on a debian 7 VPS
After a fresh install of a debian VPS, my system shows very low memory being used. I am not sure if this is even a issue. But according to 'free -m' My system is using only 21MB of RAM
...
- 171
2
votes
0
answers
757
views
PCIe card memory regions ignored on linux kernel 3.13
On my system, with kernel 3.13.0-32-generic (Ubuntu Server 14.04.1 LTS) installed, one of the PCIe boards in the system (06:00.0) is having it's memory regions ignored:
Interrupt: pin A routed to IRQ ...
- 21
2
votes
1
answer
1k
views
ps_mem.py vs top - memory usage?
Every now and again my apache server is crashing, getting an error saying the MaxClients has been reached. In my research I've gained the impression that I may be running out of memory (just checked ...
- 121
2
votes
1
answer
2k
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 ...
- 133
2
votes
0
answers
1k
views
How can I use huge pages and libhugetlbfs on a Debian EC2 PVM instance?
On my local machine (i7 9200) running Debian Wheezy amd64 I can get some significant speedups on some "big data"/HPC type stuff by:
Following the instructions here to reserve some RAM for huge pages ...
- 866
2
votes
0
answers
1k
views
How to read the address of the XSDT table, as provided by `acpidump`?
I want to access Physical memory in BSD. acpidump -t XSDT > xsdt_dump.asl it is giving:
/*
RSD PTR: OEM=ALASKA, ACPI_Rev=2.0x (2)
XSDT=0x9aae8070, length=36, cksum=164
*/
/*
XSDT: Length=...
- 21
2
votes
0
answers
81
views
Sun Fire V40z, big gap between memory reported by dmidecode and what the Linux kernel sees
I'm looking after a V40z (a loaner), running RHEL 4.8 (no, I can't update it, it's a loaner) that according to dmidecode has 8 DIMMs of 2048M each, which makes for 16GB RAM as far as I'm concerned.
...
- 1,035
2
votes
1
answer
3k
views
udisks-daemon eating up all my memory
I'm operating a little storage server on debian, over the past months I've noticed the process udisks-daemon eating up almost all available memory.
Is this just really aggressive caching or a memory ...
2
votes
0
answers
784
views
High load average, low CPU and IO (Centos 5.7)
A Drupal 7 site with CiviCRM, after running smoothly for a year on a 1&1 VPS suddenly became unresponsive. Now pages eventually load, but can take more than a minute.
Looking at resource use in ...
- 21